Born in Barcelona, Alfau emigrated with his family at the age of fourteen to the United States, where he lived the remainder of his life. Alfau earned a living as a translator; his sparse fictional and poetic output remained obscure throughout most of his life.
Alfau wrote two novels in English: Locos: A Comedy of Gestures and Chromos. Locos a metafictive collection of related short stories set in Toledo and Madrid, involving several characters that defy the wishes of the author, write their own stories, and even assume each other's roles was published by Farrar & Rinehart in 1936. The novel, for which Alfau was paid $250, received some critical acclaim, but little popular attention. The novel was republished in 1987 after Steven Moore, then an editor for the small publisher Dalkey Archive Press found the book at a barn sale in Massachusetts, read it, and contacted Alfau after a friend had found his telephone number in the Manhattan phone book. The novel's second incarnation was modestly successful, but Alfau refused payment, instructing the publisher to use the earnings from Locos to fund some other unpublished work. When Steven Moore asked if he had written any other books, Alfau produced the manuscript for Chromos, which had been resting in a drawer since 1948. Chromos to fund some other unpublished work. When Steven Moore asked if he had written any other books, Alfau produced the manuscript for Chromos, which had been resting in a drawer since 1948. Chromos, a comic story of Spanish immigrants to the United States contending with their two cultures, went on to be nominated for the National Book Award in 1990.