Barbusse wrote Le feu while he was a serving soldier. He claimed to have taken notes for the novel while still in the trenches; after being injured and reassigned from the front, he wrote and published the novel while working at the War Office in 1916.
Critical reception of the book was mixed at its publication. Its unique position of being published before the end of the war — the so-called "war book boom" took place only in the 1920s — led to its being widely read. Jacques Bertillon referred to Barbusse as a "moral witness [...] with a story to tell and re-tell."
Like many war novels, Under Fire was criticised for fictionalizing details of the war. In 1929, Jean Norton Cru, who was commissioned to critique French literature of World War I, called Under Fire "a concoction of truth, half-truth, and total falsehood."
The novel was first published in French in December 1916. It was translated into English by William Fitzwater Wray and published in June 1917 by J. M. Dent & Sons. In 2003, Penguin Press published a new translation by Robin Buss.