He was born in Budapest as the son of László Nádas and Klára Tauber. After the takeover of the Hungarian Nazis, the Arrow Cross Party on 15 October 1944, Klára Tauber escaped with her son to Bácska and Újvidék, but returned to the capital directly before the Siege of Budapest. Péter Nádas survived the siege together with his mother in the flat of his uncle, the journalist Pál Aranyossi.
Even though his parents were illegal Communists during World War II and involved with the Communist administration later on, as well, they had both their sons—Péter and Pál—baptized in the Reformed (Calvinist) Church of Pozsonyi Street. His mother died of an illness when he was 13. In 1958, his father—head of department in one of the ministries, slandered with accusations of embezzlement, then exonerated by the court of all charges—committed suicide; Péter Nádas became an orphan at 16. Magda Aranyossi became the guardian of the two children.
Between 1961 and 1963 Péter Nádas studied journalism and photography. He worked as a journalist at a Budapest magazine (Pest Megyei Hírlap) from 1965 to 1969. He also worked as a playwright and a photographer. Since 1969 he has been a freelancer.
In 1990 he married Magda Salamon (with whom he had been living since 1962). In 1984 they moved to a small village in western Hungary, Gombosszeg, where they have resided ever since, though he also has a residence in the Castle District of Buda.
In 1993, he was elected member of the Széchenyi Academy of Letters and Arts
Since the early 1970s, he has frequently spent time in Berlin, Germany attending lectures at Humboldt University or reading in the Staatsbibliothek. He has been a fellow of the Wissenschaftskolleg zu Berlin, Institute for Advanced Study. In 2006, he was elected a member of the Akademie der Künste, Berlin. He enjoys a high reputation in Germany.
After publishing volumes of short stories, he published his first novel The End of a Family Story in 1977.
He published his second novel, Book of Memories in 1986. It took Nádas eleven years to write this book. The motto of this novel is from the Gospel according to John: "But he spake of the temple of his body" (John, 2.21). In this novel, Nádas describes the world as a system of relations linking human bodies to each other. This book earned Nádas comparisons to Proust.
He published his latest novel, the three-volume Parallel Stories (I: The Mute Realm, II: In the Depths of Night, III: A Breath of Freedom) in 2005. This novel is a multitude of independent stories melt into one single narrative. It took Nádas eighteen years to complete this book. The novel has been described as "a virtuoso combination of nineteenth-century high realism with the experimentalism of the nouveau roman", while "the real narrative is that of bodies' actions on one another, their attraction and desires, their mutual memories" (Gábor Csordás). The plot is constructed around the histories of two families: one—the Lippay-Lehrs, who are Hungarian, the other—the Döhrings, who are German. These two main threads link irregularly up to one another via specific events or figures.
Nádas' other novels include Lovely Tale of Photography, Yearbook, On Heavenly and Earthly Love, and A Dialogue with Richard Swartz. Death is a recurrent theme in Nádas' work, particularly in Own death, based on his experience of clinical death.
His writing has been described as intellectual, detailed, strong, innovative and demanding.
A volume of interviews with Péter Nádas, by Zsófia Mihancsik (Nincs mennyezet, nincs födém) was published in 2006.
He has received numerous awards, including