Brunner published his first science fiction novel, Galactic Storm, in 1951 at the age of 17 under the pseudonym Gill Hunt. While his early sf work, though literate, tended more toward the space opera, his later work has tended to be more experimental and intellectual, engaging dystopian themes such as overpopulation, pollution, and the communication explosion.

His best known novel is perhaps Stand on Zanzibar which won a Hugo Award (1968) and a British Science Fiction Award (1970). Although predominantly an author of science fiction, which he has also written as Keith Woodcott, he has also published thrillers, poetry, and general fiction.