Mystery Comics Digest was published for 26 issues, from 1972 to 1975. All reprinted stories from three of Gold Key's mystery/suspense/fantasy/science fiction anthologies: Ripley's Believe It or Not!, Boris Karloff's Tales of Mystery, and Twilight Zone, in a three-issue rotation. Each issue highlighted the title it was reprinted from on the cover.

Issue focus:

• Believe It or Not! - #1, 4, 7, 10, 13, 16, 19, 22, 25
• Boris Karloff - #2, 5, 8, 11, 14, 17, 20, 23, 26
• Twilight Zone - #3, 6, 9, 12, 15, 18, 21, 24

In addition to reprints, each issue had several original works. Some of these would introduce characters who appeared in Don Glut's titles at Gold Key: Dagar, Doctor Spektor, and Tragg.

Tragg appeared in issues #3 and 9 before getting his own title.

Doctor Spektor appeared in issues #5, 10–12, and 21 before getting his own title.

Duroc/Durak, who would assist Dagar, appeared in issues #7, 14, 15. Dagar's foe, Xorkon, appeared first in #14. The first two Duroc stories were originally intended to feature Dagar.^[1]

Also, several of the creatures that Dr. Spektor fought appeared here first, including Ra-ka-tep the mummy (#1), Count Wulfstein the werewolf (#2), Simbar the werelion (#3), Baron Tibor the vampire (#4), and the Lurker in the Swamp (#7).

• Former Western Publishing scripter Mark Evanier's comments on the Gold Key digests and their eventual demise