| 0 | The Haunted Island! | cover | 1 | pencils: Bob Brown; inks: Bob Brown; letters: Ira Schnapp | Rocky Davis, Prof Haley, Ace Morgan, Red Ryan |
| 2 | Four Against Monstro | comic story | 11.67 | script: Ed Herron; pencils: Bob Brown; inks: Bob Brown; letters: Stan Starkman | Challengers of the Unknown [Red Ryan; Ace Morgan; Rocky Davis; Prof Haley]; two scientists; Monstro |
| 5 | - | letters page | 1 | script: Murray Boltinoff | |
| 6 | 80-Page Giant; The Flash | promo (ad from the publisher) | 0.5 | pencils: Carmine Infantino; inks: Murphy Anderson | Barry Allen, The Flash, The Flash, Jay Garrick |
| 8 | - | comic story | 0.67 | script: Henry Boltinoff; pencils: Henry Boltinoff; inks: Henry Boltinoff; letters: Henry Boltinoff | |
| 9 | A Comics Thrill You'll Never Forget! | promo (ad from the publisher) | 0.33 | pencils: Bob Brown; inks: Bob Brown | |
| 10 | The Haunted Island | comic story | 12.67 | script: Bill Finger; pencils: Bob Brown; inks: Bob Brown; letters: Stan Starkman | Challengers of the Unknown [Red Ryan; Ace Morgan; Rocky Davis; Prof Haley]; five unnamed mutated scientists |
| 11 | - | statement of ownership | 0.33 | letters: typeset | |
| 12 | Noisy Ghosts | comic story | 0.67 | script: Mort Drucker; pencils: Mort Drucker; inks: Mort Drucker; letters: Mort Drucker | |
| 13 | For the Very Best in Funny Comics Reading! | promo (ad from the publisher) | 0.33 | pencils: Bob Oksner; inks: Bob Oksner | Bob Hope, Jerry Lewis |
| 14 | 10 Issues of Challengers for Only $1.00 | promo (ad from the publisher) | 1 | letters: typeset | |
| 15 | Are You a Silent Witness? | public service announcement | 1 | script: Jack Schiff; pencils: Sheldon Moldoff; inks: Sheldon Moldoff; letters: Ira Schnapp | |