Weinbaum is best known for his groundbreaking science fiction short story "A Martian Odyssey", which presents a sympathetic but decidedly non-human alien, Tweel.

A film version of Weinbaum's short story "The Adaptive Ultimate" was released in 1957 under the title She Devil, starring Mari Blanchard, Jack Kelly, and Albert Dekker.

Lester del Rey declared that "Weinbaum, more than any other writer, helped to take our field out of the doldrums of the early thirties and into the beginnings of modern science fiction.

"[9] H. P. Lovecraft stated that Weinbaum's writing was ingenious, and that he stood miles above the other pulp fiction writers in his creation of genuinely alien worlds, in contrast to Edgar Rice Burroughs and his "inane" stories of "egg-laying Princesses".

Frederik Pohl wrote that before Weinbaum, science fiction's aliens "might be catmen, lizard-men, antmen, plantmen or rockmen; but they were, always and incurably, men.

... it was the difference in orientation – in drives, goals and thought processes – that made the Weinbaum-type alien so fresh and rewarding in science fiction in the mid-thirties.

"[10] According to Pohl, that Weinbaum's "revolutionary idea" was to "give some sort of three-dimensional reality to the characters", in contrast to Hugo Gernsback's "animated catalogue of gadgets".

While "Weinbaum's style was more lively than that of his genre contemporaries, and he was imaginative in background details, ... his work was ordinary pulp fiction, with routine plots, slapdash presentation, cardboard characterization, and much cliche of ideas.

Three of Weinbaum's short stories deal with Dixon Wells, a perpetually late playboy who runs afoul of the inventions of his friend and former instructor in "Newer Physics", Professor Haskel van Manderpootz, a supremely immodest genius who rates Albert Einstein as his equal or slight inferior.