| Issue | #20 |
| Published | June-July 1966 |
| Cover Price | 0.12 USD |
| Pages | 36 |
| Editing | Bob Kanigher |
| Characters | Doc Magnus; Metal Men [Gold; Platinum; Lead; Iron; Tin; Mercury; Nameless]; robot |
| Genre | superhero |
| Pencils | Ross Andru (signed) |
| Inks | Mike Esposito (signed) |
| Characters | Batman; Blockbuster; Superman; Superboy; Krypto; Lois Lane |
| Pencils | various; Curt Swan |
| Inks | various |
| Notes | Ad for various TV shows and a Broadway Musical based on DC Comics characters. Printed in black-and-white on inside front cover. |
| Characters | Doc Magnus; Metal Men [Gold; Platinum; Lead; Iron; Tin; Mercury; Nameless]; Dr. Yes's robot; Dr. Yes; unamed friend of Doc Magnus' |
| Synopsis | The Metal Men reconstruct Dr. Yes's robot with a responsometer, to have it lead them to Dr. Yes. But Dr. Yes turns the tables and the Metal Men have to fight and destroy the robot again, and still do not find his lair. |
| Genre | superhero |
| Script | Bob Kanigher |
| Pencils | Ross Andru |
| Inks | Mike Esposito |
| Notes | Story is broken into 3 parts. Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics (May 2007). Schwartz kept editorial records for Robert Kanigher who edited this issue. |
| Characters | Joseph Lister |
| Synopsis | Information on bone structure of the hand and foot, and properties of the element Mercury, and compound carbolic acid. |
| Genre | fact |
| Notes | Appears after page 6 of story sequence 1 and before story sequence 4. |
| Characters | an old sea captain; two boys |
| Synopsis | After telling the boys some tales, the captain takes them to the library where they can travel anywhere just by reading. |
| Genre | fact |
| Script | Jack Schiff |
| Pencils | Sheldon Moldoff |
| Inks | Sheldon Moldoff |
| Letters | Ira Schnapp |
| Notes | Appears after story sequence 3 and before page 7 of story sequence 1. A list by Lionel English also gives the penciller and inker as "Morris Waldinger" in one of the issues this PSA appears in. Other creator credits from a list by Lionel English. |
| Script | Bob Kanigher |
| Letters | typeset |
| Notes | Appears after page 12 of story sequence 1 and before sequence 6. Letters from: Gary Rothy; Ken Nathanson; Brian Hoye. |
| Characters | Cap |
| Synopsis | A list of items to have handy before you start to build a plastic model. |
| Genre | fact |
| Script | Henry Boltinoff |
| Pencils | Henry Boltinoff |
| Inks | Henry Boltinoff |
| Letters | Henry Boltinoff |
| Notes | Appears between story sequence 5 and page 13 of story sequence 1. Idea from Gerald Greitzer, who was awarded the original art. |
| Synopsis | Information on ratios of paramecium division rates, thickness of the ozone layer, aging of humans vs. dogs, and sunlight over the earth's surface. |
| Genre | fact |
| Characters | G.I. Joe; Andy; George |
| Synopsis | Andy and George try out G.I. Joe's new diving suit set. |
| Notes | Printed on inside back cover in black-and-white. Ad for G.I. Joe Diving Suit; includes a coupon to join the G.I. Joe Club. |