Piero Dorazio was born in Rome where, after having finished his classical studies, he studied architecture for four years.
In the first post-war period he attended the studio of Renato Guttuso, but soon he moved away from the theses of socialist realism and joined the movement of abstractionism.
In 1947 he was one of the signatories of the Forma 1 Group manifesto, together with Ugo Attardi, Pietro Consagra, Mino Guerrini, Achille Perilli, Antonio Sanfilippo, Giulio Turcato and Carla Accardi in open opposition to socialist realism, expressionism, the Scuola Romana, denouncing the intrusion of politics into artistic creation. In 1947, he also won a scholarship from the École nationale supérieure des beaux-arts in Paris, where he lived for a year.
With Perilli and Guerrini, in 1950 he opened the library-gallery "L'Age d'Or" in via del Babuino, Rome, a cooperative between artists for the dissemination of avant-garde art and international press. "L'Age d'Or" in 1951 will merge with the group "Origine" of Mario Ballocco, Alberto Burri, Giuseppe Capogrossi, Ettore Colla, creating the "Origine Foundation", in which Colla and Dorazio publish the magazine "Visual Arts".
From 1953 he moved to the United States, in this period Dorazio also concentrated on the study of the writings of Vasilij Vasil'evič Kandinskij, whose theory on the immaterial aspects of painting would greatly influence him.
In 1961 in Berlin, he took part in the activity of the Zero Group together with Heinz Mach, Otto Pine and Gunter Uecher, of which he organized the first American exhibition in 1964, hosted by the University of Pennsylvania.
In 1974 he moved to Todi, in Umbria, and here he continued to create until 2005, the year of his death.