Ace Doubles, D-series cover

American company Ace Books began publishing genre fiction starting in 1952. Initially these were mostly in the attractive tête-bêche format, but they also published a few single volumes, in the early years, and that number grew until the doubles stopped appearing in about 1978. The tête-bêche format was discarded in 1973, but future double novels were continued for a while.

Between 1952 and 1968, the books had a letter-series identifier; after that date they were given five-digit numeric serial numbers. The list given here covers every Ace Double published between 1952 and 1978, for all genres. It gives a date of publication; in all cases this refers to the date of publication by Ace, and not the date of original publication of the novels. For more information about the history of these titles, see Ace Books, which includes a discussion of the serial numbering conventions used and an explanation of the letter-code system.