| Issue | #21 |
| Published | July 1969 |
| Cover Price | 0.25 USD |
| Pages | 68 |
| Editing | Stan Lee |
| Characters | Avengers [Thor; Iron Man [Tony Stark]; Wasp; Giant-Man [Henry Pym]]; X-Men [Cyclops; Marvel Girl; Iceman; Beast; Angel]; Hulk; Sub-Mariner |
| Genre | Superhero |
| Pencils | Marie Severin |
| Inks | John Romita |
| Genre | Superhero |
| Script | Stan Lee |
| Pencils | Jack Kirby |
| Inks | Paul Reinman |
| Letters | Sam Rosen |
| Reprinted | from Avengers, The (Marvel, 1963 series) #3 (January 1964) |
| Characters | Avengers [Iron Man [Tony Stark]; Thor; Giant-Man [Henry Pym]]; Sub-Mariner; Hulk |
| Genre | Superhero |
| Pencils | Jack Kirby |
| Inks | Paul Reinman |
| Reprinted | from Avengers, The (Marvel, 1963 series) #3 (January 1964) |
| Genre | Superhero |
| Script | Stan Lee |
| Pencils | Jack Kirby |
| Inks | Paul Reinman |
| Letters | Sam Rosen |
| Reprinted | from X-Men (Marvel, 1963 series) #2 (November 1963) |
| Characters | Cyclops |
| Genre | Superhero |
| Pencils | Jack Kirby |
| Inks | Chic Stone |
| Letters | Sam Rosen |
| Reprinted | from X-Men (Marvel, 1963 series) #6 (July 1964) |
| Characters | Marvel Girl |
| Genre | Superhero |
| Pencils | Jack Kirby |
| Inks | Chic Stone |
| Letters | Art Simek; Sam Rosen |
| Reprinted | from X-Men (Marvel, 1963 series) #9 (January 1965) |
| Characters | Beast |
| Genre | Superhero |
| Pencils | Jack Kirby |
| Inks | Chic Stone |
| Letters | Sam Rosen |
| Reprinted | from X-Men (Marvel, 1963 series) #8 (November 1964) |
| Pencils | Gene Colan; ? |
| Inks | Mike Esposito [as Mickey Demeo] ; ? |
| Colors | Stan Goldberg; ? |
| Notes | Letters from Danny English, Carl Gafford, George Bognen, Anthony Kowalik, Max Kerpelman, Nelson Walter, Glenn Bornemann and Leslie Koorhan, includes a panel from the Guardians of the Galaxy story in Marvel Super-Heroes (Marvel, 1967 series) #18. |