Beatriz Guido was born in Argentina to architect Ángel Guido and actress Berta Eirin. She studied at the University of Buenos Aires and published her first novel, La casa del ángel, in 1954. Following the end of a brief first marriage, in 1959 she married Leopoldo Torre Nilsson, a leading film director and screenwriter. They worked together and adapted several of her works for the screen.
For many years, she was considered a "right-wing writer" by the Argentine government due to her opposition to the Perónist regime. In 1984, after the return of democracy to Argentine, she was appointed cultural attaché of the Argentine Embassy in Spain. She died of a heart attack at age 63.