He took up writing at an early age but did not consider his works fit for publishing until the late 1950s.
In 1959, he published his autobiography, Pierrot-la-lune, which was a critical success. He gained notoriety with his 1962 play Lieutenant Tenant, but his later works were commercially unsuccessful. Pierre Gripari kept publishing his books thanks to the support of publisher L'Age d'Homme, but only gained real fame and success in the late 1970s, thanks to the publishing of his children's book Contes de la rue Broca. Until his death, he was more known to French audiences as a children's author.
He was also theater critic for the newspaper Écrits de Paris.
He died December 23, 1990 at St. Joseph hospital in Paris.