[4] Del Rey first started publishing stories in pulp magazines in the late 1930s, at the dawn of the so-called Golden Age of Science Fiction.

The December 1938 issue featured his story "Helen O'Loy" which was selected for the prestigious anthology The Science Fiction Hall of Fame.

By the end of 1939 he had also placed stories in Weird Tales (edited by Farnsworth Wright) and Unknown (Campbell),[5] which featured more horror and more fantasy respectively.

[2] He continued publishing novels, as well as short fiction, both under his primary pseudonym Lester del Rey as well as a number of other pen names, at a fast pace through the 1950s and the early sixties.

[11] After science fiction gained respectability and began to be taught in classrooms, del Rey stated that academics interested in the genre should "get out of my ghetto.

Del Rey was a member of a literary banqueting club, the Trap Door Spiders, which served as the basis of Isaac Asimov's fictional group of mystery solvers, the Black Widowers.

The typical del Rey story problem is that of a good and faithful being trying to understand a complex situation which prevents his immediately knowing the decent thing to do.

When he writes a story whose problem becomes apparent only in the last paragraphs, this is frequently the nature of his "trick" ending—the mood is not shock but sorrow; the payoff is not in some irrevocable destruction of this personality but in the reader's realization that even a decent individual must pay the price of ignorance.