| 0 | Flash | cover | 1 | pencils: Carmine Infantino; inks: Frank Giacoia; colors: Allen Passalaqua | Flash [Barry Allen] |
| 1 | - | blank page(s) | 2 | | |
| 2 | Showcase Presents Showcase | credits, title page | 1 | letters: typeset | |
| 3 | Table of Contents | table of contents | 4 | letters: typeset | |
| 4 | Showcase #1 | cover reprint (on interior page) | 1 | pencils: John Prentice; inks: John Prentice; letters: Ira Schnapp | Fireman Farrell |
| 5 | The Story Behind Showcase | comic story | 1 | script: Jack Schiff; pencils: Win Mortimer; inks: Win Mortimer; letters: Ira Schnapp | Larry Blake; National Comics' editor |
| 6 | The School for Smoke-Eaters | comic story | 8 | script: Arnold Drake; pencils: John Prentice; inks: John Prentice | Fireman Farrell; Red Miller; Clark; Noonan; Fox; Gainer |
| 7 | Fire under the Big Top | comic story | 8 | script: Arnold Drake; pencils: John Prentice; inks: John Prentice | Fireman Farrell; Fire Lieutenant Reiner; Phil Baylor |
| 8 | Fourth Alarm | comic story | 8 | script: Arnold Drake; pencils: John Prentice; inks: John Prentice | Fireman Ferrell; Edgar R. Meadow; Captain Walsh |
| 9 | Showcase #2 | cover reprint (on interior page) | 1 | pencils: Irv Novick; inks: Irv Novick; letters: Ira Schnapp | |
| 10 | Rider of the Winds! | comic story | 8 | pencils: Joe Kubert; inks: Joe Kubert | Eagle Feather (an Indian boy); Godfather (an eagle); Black Lightning (a mountain lion) |
| 11 | Outcast Heroes! | comic story | 8 | script: Robert Kanigher; pencils: Ross Andru; inks: Mike Esposito | Dan; Aunt Jane |
| 12 | Runaway Bear | comic story | 8 | pencils: Russ Heath; inks: Russ Heath | Billy, a circus bear; a lion; an elephant; a hunter; a park ranger |
| 13 | Showcase #3 | cover reprint (on interior page) | 1 | pencils: Jerry Grandenetti; inks: Jerry Grandenetti | |
| 14 | "The Frogmen" Part I The Making of a Frogman! | comic story | 8 | script: Robert Kanigher; pencils: Russ Heath; inks: Russ Heath; letters: Gaspar Saladino | Sardine; Shark; Whale; kids (flashback); Mom (flashback); Drill Instructor; frogmen recruits |
| 15 | Part II of "The Frogmen!" Flying Frogmen | comic story | 6 | script: Robert Kanigher; pencils: Russ Heath; inks: Russ Heath; letters: Gaspar Saladino | Sardine; Shark; Whale |
| 16 | Part III of "The Frogmen!" Silent War! | comic story | 10 | script: Robert Kanigher; pencils: Russ Heath; inks: Russ Heath; letters: Gaspar Saladino | Sardine; Shark; Whale |
| 17 | Showcase #4 | cover reprint (on interior page) | 1 | pencils: Carmine Infantino, Robert Kanigher; inks: Joe Kubert; letters: Ira Schnapp | Flash [Barry Allen] |
| 18 | Mystery of the Human Thunderbolt! | comic story | 12 | script: Robert Kanigher; pencils: Carmine Infantino; inks: Joe Kubert | The Flash [Barry Allen] (introduction, scientist, origin); The Flash [Jay Garrick] (image only); Iris West (introduction); The Turtle Man [aka later as The Turtle] (villain, introduction) |
| 19 | The Man Who Broke the Time Barrier! | comic story | 10 | script: John Broome; pencils: Carmine Infantino; inks: Joe Kubert | The Flash [Barry Allen]; Mazdan (villain) |
| 20 | Showcase #5 | cover reprint (on interior page) | 1 | pencils: Ruben Moreira; inks: Ruben Moreira; letters: Ira Schnapp | |
| 21 | The Greatest Villain of All Time | comic story | 8 | script: Jack Miller; pencils: Mort Meskin; inks: Mort Meskin | Lt. Harry Fowler; Sergeant Collins; Ben Gatewood (Producer); Leif Conrad (Director); Danny Tell (Public Relations); Otto Sands (Actor) |
| 22 | The Two Faces of Mr. X | comic story | 7.66 | script: Jack Miller; pencils: Curt Swan; inks: Sy Barry | Don Reed; FBI agents; Alex Tate (crime boss); gangsters |
| 23 | The Human Eel | comic story | 8 | script: Jack Miller; pencils: Bill Ely; inks: Bill Ely | Agent Drew; The Human Eel; Zorac; police of many nations |
| 24 | Showcase #6 | cover reprint (on interior page) | 1 | pencils: Jack Kirby; inks: Jack Kirby | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 25 | The Secrets of the Sorcerer's Box! [Chapter One] | comic story | 6 | script: Jack Kirby, Joe Simon, Dave Wood; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein; letters: Ben Oda | Challengers of the Unknown [Ace Morgan; Prof Haley; Red Ryan; Rocky Davis] (introduction for all, origin); un-named sailors; un-named citizens; Mr. Morelian (villain, introduction, death) |
| 26 | Chapter Two Dragon Seed! | comic story | 6 | script: Jack Kirby, Joe Simon, Dave Wood; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein; letters: Ben Oda | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 27 | Chapter Three The Freezing Sun! | comic story | 6 | script: Jack Kirby, Joe Simon, Dave Wood; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein; letters: Ben Oda | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 28 | Chapter Four The Whirling Weaver! | comic story | 6 | script: Jack Kirby, Joe Simon, Dave Wood; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein; letters: Ben Oda | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 29 | Showcase #7 | cover reprint (on interior page) | 1 | pencils: Jack Kirby; inks: Jack Kirby | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 30 | ULTIVAC Is Loose [Chapter One] | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis]; June Robbins (first appearance); Felix Hesse (first appearance); ULTIVAC (first appearance) |
| 31 | Chapter Two A Challenger Must Die! | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 32 | Chapter Three The Fearful Millions | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 33 | Chapter Four The Fatal Prediction! | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby, Marvin Stein | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 34 | Showcase #8 | cover reprint (on interior page) | 1 | pencils: Carmine Infantino; inks: Frank Giacoia; letters: Ira Schnapp | Flash [Barry Allen] |
| 35 | The Secret of the Empty Box! | comic story | 12 | script: Robert Kanigher; pencils: Carmine Infantino; inks: Frank Giacoia | Flash [Barry Allen]; Iris West |
| 36 | The Coldest Man on Earth! | comic story | 12 | script: John Broome; pencils: Carmine Infantino; inks: Frank Giacoia | Flash [Barry Allen]; Captain Cold [Leonard Snart](first appearance; origin; villain) |
| 37 | The Race of Wheel and Keel | comic story | 3 | script: Gardner Fox; pencils: Gil Kane; inks: Harry Lazarus | John Butterfield; Harrison |
| 38 | Showcase #9 | cover reprint (on interior page) | 1 | pencils: Al Plastino; inks: Al Plastino; letters: Ira Schnapp | Lois Lane; Superman |
| 39 | The Girl in Superman's Past | comic story | 8 | script: Jerry Coleman; pencils: Al Plastino; inks: Al Plastino | Lois Lane; Lana Lang; Superman [Clark Kent] |
| 40 | The New Lois Lane | comic story | 8 | script: Otto Binder; pencils: Ruben Moreira; inks: Al Plastino | Superman [Clark Kent]; Lois Lane; "Con" Conners |
| 41 | Mrs. Superman | comic story | 8 | script: Otto Binder; pencils: Al Plastino; inks: Al Plastino | Superman; Jimmy Olsen; Lulu Lyons (introduction) |
| 42 | Showcase #10 | cover reprint (on interior page) | 1 | pencils: Wayne Boring; inks: Stan Kaye; letters: Ira Schnapp | Lois Lane; Superman |
| 43 | The Jilting of Superman | comic story | 8 | script: Otto Binder; pencils: Wayne Boring; inks: Stan Kaye | Lois Lane; Superman; Tony Lester |
| 44 | The Sightless Lois Lane | comic story | 8 | script: Jerry Coleman; pencils: Wayne Boring; inks: Stan Kaye | Lois Lane; Superman; Perry White; Deadline (dog) |
| 45 | The Forbidden Box from Krypton | comic story | 8 | script: Otto Binder; pencils: Wayne Boring; inks: Stan Kaye | Lois Lane; Superman; Perry White; Jimmy Olsen; Jor-El (flashback); Lara (flashback) |
| 46 | Showcase #11 | cover reprint (on interior page) | 1 | pencils: Jack Kirby; inks: Jack Kirby | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis]; General Tolek |
| 47 | The Day the Earth Blew Up [Chapter One] | comic story | 7 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Marvin Stein; letters: Pat Gordon | Challengers of the Unknown [Ace Morgan; Rocky Davis; Professor Haley; Red Ryan]; Carl Jackson; Warren Moss; Commander Lockwood; Colonel Price; General Tolek (villain); Garnat (villain); other Tyrans (villains) |
| 48 | Chapter Two The Tyrans | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Marvin Stein; letters: Pat Gordon | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 49 | Chapter Three The Thing That Came Out of the Sea | comic story | 6 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Marvin Stein; letters: Pat Gordon | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 50 | Chapter Four One Minute to Doom | comic story | 5 | script: Dave Wood, Jack Kirby; pencils: Jack Kirby; inks: Marvin Stein; letters: Pat Gordon | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 51 | Showcase #12 | cover reprint (on interior page) | 1 | pencils: Jack Kirby; inks: Jack Kirby, Roz Kirby; letters: Ira Schnapp | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 52 | The Menace of the Ancient Vials! Chapter 1 | comic story | 6 | script: Dave Wood; pencils: Jack Kirby; inks: Leonard Starr; letters: Artie Simek | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis]; Amos Hunter; VILLAINS: Brommer; Gortz; Karnak, Kraken |
| 53 | Chapter Two The Fire Being! | comic story | 6 | script: Dave Wood; pencils: Jack Kirby; inks: Leonard Starr; letters: Artie Simek | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 54 | Chapter 3 The Demon From the Depths | comic story | 6 | script: Dave Wood; pencils: Jack Kirby; inks: Leonard Starr; letters: Artie Simek | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 55 | Chapter 4 The Deadly Duplicates! | comic story | 6 | script: Dave Wood; pencils: Jack Kirby; inks: Leonard Starr; letters: Artie Simek | Challengers of the Unknown [Ace Morgan; Professor Haley; Red Ryan; Rocky Davis] |
| 56 | Showcase #13 | cover reprint (on interior page) | 1 | pencils: Carmine Infantino; inks: Frank Giacoia; letters: Ira Schnapp | Flash [Barry Allen] |
| 57 | Around the World in 80 Minutes! | comic story | 13.67 | script: Robert Kanigher; pencils: Carmine Infantino; inks: Joe Giella; letters: Gaspar Saladino | Flash [Barry Allen]; Iris West; Le Chat Noir (villain); El Claw (villain); Princess Tara |
| 58 | Master of the Elements! | comic story | 12 | script: John Broome; pencils: Carmine Infantino; inks: Frank Giacoia; letters: Gaspar Saladino | Flash [Barry Allen]; Iris West; Mr. Element [Albert Desmond](first appearance; origin; villain; later called Dr. Alchemy); Argon (villain); Radon (villain); Krypton (villain); Xenon (villain) |
| 59 | Showcase #14 | cover reprint (on interior page) | 1 | pencils: Carmine Infantino; inks: Frank Giacoia, Joe Giella; letters: Ira Schnapp | Flash [Barry Allen] |
| 60 | Giants of the Time-World! | comic story | 13 | script: Robert Kanigher; pencils: Carmine Infantino; inks: Frank Giacoia | Flash [Barry Allen]; Iris West |
| 61 | The Man Who Changed the Earth! | comic story | 12 | script: John Broome; pencils: Carmine Infantino; inks: Frank Giacoia | Flash [Barry Allen]; Iris West; Dr. Alchemy [Albert Desmond](villain; origin; formerly Mr. Element); Ben Sniper |
| 62 | Showcase #15 | cover reprint (on interior page) | 1 | pencils: Bob Brown; inks: Bob Brown; letters: Ira Schnapp | Space Ranger |
| 63 | The Great Plutonium Plot | comic story | 12 | script: Gardner Fox, Edmond Hamilton; pencils: Bob Brown; inks: Bob Brown | Space Ranger [Rick Starr] (Introduction); Jarko; Gurph; Myra Mason; Thaddeus Starr; Cryll; Zandor |
| 64 | The Robot Planet | comic story | 12 | script: Gardner Fox, Edmond Hamilton; pencils: Bob Brown; inks: Bob Brown | Space Ranger [Rick Starr]; Myra Mason; Cryll; Danaan |
| 65 | Showcase #16 | cover reprint (on interior page) | 1 | pencils: Bob Brown; inks: Bob Brown; letters: Ira Schnapp | The Space Ranger [Rick Starr]; Myra Mason; Ragnar-Ell |
| 66 | The Secret of the Space Monster | comic story | 12 | script: Gardner Fox, Edmond Hamilton; pencils: Bob Brown; inks: Bob Brown | The Space Ranger [Rick Starr]; President Thaddeus Starr; Myra Mason (Rick's secretary); Cryll (a shape-shifting alien sidekick); Captain Jones; rebels from Korth near Procyon; Korthan councillors |
| 67 | The Riddle of the Lost Race | comic story | 12 | script: Gardner Fox, Edmond Hamilton; pencils: Bob Brown; inks: Bob Brown | The Space Ranger [Rick Starr]; Cryll; Myra Mason; a Mercurian Oceton hunter; a gang led by the Plutonian Ragnar-Ell; Evan Blanchard (a space archaeologist) |
| 68 | Showcase #17 | cover reprint (on interior page) | 1 | pencils: Gil Kane; inks: Gil Kane; letters: Ira Schnapp | Adam Strange |
| 69 | Secret of the Eternal City! | comic story | 14.33 | script: Gardner Fox, Edmond Hamilton; pencils: Mike Sekowsky; inks: Frank Giacoia, Joe Giella; letters: Gaspar Saladino | Adam Strange (introduction, origin); Alanna [aka Allana] (introduction); Sardath (Alanna's father scientist, introduction); inhabitants of Samakand; The Eternals (villains, introduction for all) |
| 70 | The Planet and the Pendulum! | comic story | 9.67 | script: Gardner Fox, Edmond Hamilton; pencils: Mike Sekowsky; inks: Frank Giacoia, Joe Giella | Adam Strange; Alanna; Sardath; citizens of New Ranagar; barbarians of the tribe of Zoora from the city Yardana (villains); invaders from Morleen (villains) |
| 71 | Showcase #18 | cover reprint (on interior page) | 1 | pencils: Gil Kane; inks: Joe Giella; letters: Ira Schnapp | Adam Strange; Alanna |
| 72 | Invaders from the Atom Universe! | comic story | 14.33 | script: Gardner Fox; pencils: Mike Sekowsky; inks: Bernard Sachs; letters: Gaspar Saladino | Adam Strange; Rann; Alanna; Vrenn chieftain; The Vrenn |
| 73 | The Dozen Dooms of Adam Strange! | comic story | 9.67 | script: Gardner Fox; pencils: Mike Sekowsky; inks: Joe Giella | Adam Strange; Alanna; Tak Vall (first appearance; villain); Moora (first appearance; villain) |
| 74 | Showcase #19 | cover reprint (on interior page) | 1 | pencils: Gil Kane; inks: Bernard Sachs; letters: Ira Schnapp | Adam Strange; Alanna |
| 75 | Challenge of the Star-Hunter! | comic story | 12.33 | script: Gardner Fox; pencils: Mike Sekowsky; inks: Joe Giella; letters: Gaspar Saladino | Adam Strange; Alanna; Sardath; Leothric (first appearance; villain) |
| 76 | Mystery of the Mental Menace! | comic story | 11.67 | script: Gardner Fox; pencils: Mike Sekowsky; inks: Sy Barry | Adam Strange; Alanna; Zakkad (first appearance; villain) |
| 77 | Showcase #20 | cover reprint (on interior page) | 1 | pencils: Bob Brown; inks: Bob Brown; letters: Ira Schnapp | Rip Hunter |
| 78 | Prisoners of 100 Million B.C. [Chapter 1] | comic story | 8.67 | script: Dave Wood; pencils: Ruben Moreira; inks: Ruben Moreira | Rip Hunter (introduction; origin); Jeff Smith; Bonnie Baxter; Corky Baxter |
| 79 | Chapter 2 The Modern-Day Cavemen | comic story | 6.67 | script: Dave Wood; pencils: Ruben Moreira; inks: Ruben Moreira | Rip Hunter; Jeff Smith; Bonnie Baxter; Corky Baxter |
| 80 | Chapter 3 The Great Beast Stampede | comic story | 7.67 | script: Dave Wood; pencils: Ruben Moreira; inks: Ruben Moreira | Rip Hunter; Jeff Smith; Bonnie Baxter; Corky Baxter |
| 81 | Showcase #21 | cover reprint (on interior page) | 1 | pencils: Mike Sekowsky; inks: Joe Giella; letters: Ira Schnapp | Rip Hunter; Jeff Smith; Circe |
| 82 | The Secret of the Lost Continent [Chapter 1] | comic story | 9.67 | script: Jack Miller; pencils: Mike Sekowsky; inks: Joe Giella | Rip Hunter; Jeff Smith; Bonnie Baxter; Corky Baxter [Bonnie's kid brother]; Alexander the Great; warriors |
| 83 | Chapter 2 The Forbidden Island | comic story | 7.67 | script: Jack Miller; pencils: Mike Sekowsky; inks: Joe Giella | Rip Hunter; Jeff Smith; Bonnie Baxter; Corky Baxter; Circe; (fake) centaurs; Cretan sailors |
| 84 | Chapter 3 The Doomed Continent | comic story | 6.67 | script: Jack Miller; pencils: Mike Sekowsky; inks: Joe Giella | Rip Hunter; Jeff Smith; Bonnie Baxter; Corky Baxter; Aliens from Jexjara; R'Del (Chief Scientist); D'Zar (dictator) |
| 85 | - | blank page(s) | 1 | | |
| 86 | DC Comics | promo (ad from the publisher) | 4 | letters: typeset | |
| 87 | Showcase Volume 1 | promo (ad from the publisher) | 1 | letters: typeset | |