Born in Holguín, Cuba. Essayist, playwright, short story writer and novelist, Arenas learned to write and read from his mother, and when he was 15 years old, he joined the rebel forces against the military dictator, Fulgencio Batista.

After the Revolution, he turned to his home town, Holguín, where he obtained a scholarship to study agricultural accounting, after which he moved to the Sierra Maestra to work at a poultry farm. Unhappy with his job and pastoral life, Arenas left for Havana to attend a training programme for economic planners. In 1963 he became a staff member of the National Library, where he realized he wanted to become a writer.

In 1973 he was imprisoned for his homosexuality and his opposition against the Fidel Castro regime. In 1980 he went to the USA, where he committed suicide, by taking an overdose of drugs and alcohol, when he discovered he had Aids.

Arenas is one of the most important writers that Cuba has produced since the Revolution of 1959, and his work has been translated into several languages. In 2000 Julian Schnabel made a movie about his life: Before night falls.