Adolfo Bioy Casares was born in Buenos Aires, the grandson of a wealthy landowner and dairy processor, and the descendant of Patrick Lynch, a successful Irish emigrant. He wrote his first story ("Iris y Margarita") at the age of eleven. He was a friend and frequent collaborator of Jorge Luis Borges and wrote many stories with him under the pseudonym of H. Bustos Domecq.

Bioy and Borges were introduced in 1932 by Victoria Ocampo, whose sister, Silvina Ocampo (1903—1994), Bioy Casares was to marry in 1940. In 1954 they adopted Bioy’s daughter with another woman; Marta Bioy Ocampo (1954—94) was killed in an automobile accident just three weeks after Silvina Ocampo’s death, leaving two children. The estate of Silvina Ocampo and Adolfo Bioy Casares was awarded by a Buenos Aires court to yet another love child of Adolfo Bioy Casares, Fabián Bioy, shortly before Fabián Bioy died, aged 40, in February 2006.

Bioy won several awards, including the Gran Premio de Honor of SADE (the Argentine Society of Writers, 1975), the French Légion d'honneur (1981), the title of Illustrious Citizen of Buenos Aires (1986), and the Premio Miguel de Cervantes (awarded to him in 1991 in Alcalá de Henares).

Adolfo Bioy Casares is buried in La Recoleta Cemetery, Buenos Aires.

In 2006 Ediciones Destino published a book of Bioy's diary entries on Borges, numbering 1663 pages of anecdotes, witticisms and observations.

The best-known novel by Bioy Casares is La invención de Morel (The Invention of Morel). It is the story of a man who, evading justice, escapes to an island said to be infected with a mysterious fatal disease. Struggling to understand why everything seems to repeat, he realizes that all the people he sees there are actually recordings, made with a special machine, invented by Morel, which is able to record not only three-dimensional images, but also voices and scents, making it all indistinguishable from reality. The story mixes realism, fantasy, science fiction and terror. Borges wrote a famous prologue in which he called it a work of "reasoned imagination" and linked it to H. G. Wells' oeuvre. Both Borges and Octavio Paz described the novel as "perfect." The story is held to be the inspiration for Alan Resnais's Last Year in Marienbad and also an influence on the TV series Lost.

Novels

• La invención de Morel (1940, translated into English as The Invention of Morel, or "Morel's Invention" ISBN 1-59017-057-1)
• Plan de evasión (1945, translated into English as A Plan for Escape, ISBN 1-55597-107-5)
• El sueño de los héroes (1954, translated into English as Dream of Heroes, ISBN 0-7043-2634-5)
• Diario de la guerra del cerdo (1969, translated into English as Diary of the War of the Pig, ISBN 0-07-073742-8)
• Dormir al Sol (1973, translated into English 1978 as Asleep in the Sun, ISBN 0-89255-030-9)
• La aventura de un fotógrafo en La Plata (1985, translated into English as The Adventures of a Photographer in La Plata, ISBN 0-7475-0798-8)
• Un campeón desparejo (An Uneven Champion, 1993)

Short Story Collections

• Prólogo (Prologue, 1929)
• 17 disparos contra el porvenir (17 Shots Against the Future, 1933)
• La estatua casera (The Household Statue, 1936)
• La trama celeste (The Celestial Plot, 1948)
• Luis Greve, muerto (Luis Greve, Deceased, 1937)
• Las vísperas de Fausto (Faust's Eve, 1949)
• Historia prodigiosa (A Remarkable History, 1956)
• Guirnalda con amores (Guirnalda with Loves1959)
• El lado de la sombra (The Shady Side, 1962)
• El gran serafín (The Great Seraph, 1967)
• El héroe de las mujeres (The Hero of Women, 1978)
• Historias desaforadas (Colossal Stories, 1986)

Generally, these Spanish-language collections have not been systematically translated into English. English language collections include:

• The Russian Doll and Other Stories (ISBN 0-8112-1211-4)
• Selected Stories (ISBN 0-8112-1275-0)

Letters

• En viaje (Travelling, 1996), letters to Silvina

Works in collaboration

With Jorge Luis Borges

• Seis problemas para don Isidro Parodi (1942, translated into English as Six Problems for Don Isidro Parodi, ISBN 0-525-48035-8)
• Dos fantasías memorables (Two Memorable Fantasies, 1946)
• Un modelo para la muerte (A Model for Death, 1946)
• Cuentos breves y extraordinarios (Short and Amazing Stories, 1955)
• Crónicas de Bustos Domecq (1967, translated into English as Chronicles of Bustos Domecq, ISBN 0-525-47548-6)
• Libro del cielo y del infierno, (The Book of Heaven and Hell, 1960)
• Nuevos cuentos de Bustos Domecq (New Stories by Bustos Domecq, 1977)

Dos fantasías memorables and Un modelo para la muerte were originally published in private printings of only 300 copies. The first commercial printings were published in 1970.

With Silvina Ocampo

• Los que aman, odian (Those Who Love, Hate, 1946)

Screenplays

With Jorge Luis Borges

• Los orilleros (1955, The Hoodlums)
• El paraíso de los creyentes (1955, The Paradise of the Believers)
• Invasión (1969, Invasion)
• The Others (1974)

About The Invention of Morel

• Borges on Morel
• Review of 'The Invention of Morel' by Seamus Sweeney on nthposition.com
• Prologue to The Invention of Morel (in Spanish)
• Review of 'The Invention of Morel' on waggish.
• Adolfo Vásquez Rocca, La Invención de Morel; Defensa para sobrevivientes Luke nº 77, September 2006 - ISSN 1578-8644.
• Adolfo Vásquez Rocca, De la invención de Morel a los simulacros de Baudrillard; La nueva ecología de los mass media, Tendencias 21, 17 September 2006.