Marvel Two-in-One continued from the team-up stories starring the Thing in the final two issues of Marvel Feature and lasted for 100 issues from January 1974 through June 1983. Seven annuals were also published. Artist Ron Wilson began his long association with the title with issue #12 (November 1975) and worked on it throughout its run. With issue #17, the series had a crossover with Marvel Team-Up #47, which featured Spider-Man. The second Marvel Two-in-One Annual was a crossover with Avengers Annual #7 both of which were written and drawn by Jim Starlin. The "Project Pegasus" storyline in Marvel Two-in-One #53-58 saw the introduction of the name "Quasar" for the Wendell Vaughn character and the transformation of Wundarr into the Aquarian.
Many notable comics creators contributed to the series, including Steve Gerber, Frank Miller, Jack Kirby (who did pencils on several covers during its run), John Byrne, John Buscema, George Pérez and Marv Wolfman.
Marvel Two-In-One ended after one hundred issues and was immediately replaced with a Thing solo series.