The Avon Science Fiction Readers, published during 1951-1952, were seen as companion publications for the Avon Fantasy Readers, with both titles issued in the same format and both edited by Donald A. Wollheim.
The SF Readers were only three in number, but were followed by two issues of an Avon Science Fiction and Fantasy Reader in 1952. These combined readers were edited by Sol Cohen after Wolheim had left Avon for Ace Books.
The SF Readers were not as popular as the Fantasy Readers, possibly because they were in competition with the many SF magazines being published at the same time.
There was always controversy over whether or not the Readers were magazines or paperback book anthologies reprinting stories that had been published in the magazines. Wollheim and the publisher claimed they were books of reprinted materiais. When Cohen took over and began pubishing original material and using interior illustrations, the distinction was less clear.