Published from 1952? to 1974?.
If, subtitled Worlds of Science Fiction, was launched in March 1952, the creation of James L. Quinn of the Quinn Publishing Company, not to be confused with Robert Guin, who later published both if and its sister magazines, including Galaxy Science Fiction. The title If had previously been used by Con Pederson in 1948 for a science fiction fanzine).
The original cover bore a distinctive if in oversized lower-case letters, with a line across the top of the logo reading "Worlds of Science Fiction" with a rectangle that enclosed most of the large "if" letters and the words "Worlds of," which from the beginning suggested the title could be read as "Worlds of if". In 1972 Worlds of if was made the official name of the magazine, so that issues after 1972 are sometimes indexed separately.
In 1974 If ceased publication and was incorporated into Galaxy.
