From the early 1960s until 1969, Pohl served as editor of "Galaxy Science Fiction" and "Worlds of if" magazines, taking over after the ailing H. L. Gold could no longer continue working "around the end of 1960". Under his leadership, "if" won the Hugo Award for Best Professional Magazine for 1966, 1967 and 1968. Pohl hired Judy-Lynn del Rey as his assistant editor at "Galaxy" and "if". He also served as editor of "Worlds of Tomorrow" from its first issue in 1963 until it was merged into "if" in 1967.