Italian sculptor, painter, ceramicist, and designer. He was born at Pescara and studied at the Academy in Rome. The son of a traditional sculptor, he showed a preference for carving in stone (including marble) that was unusual in artists of his generation. Initially, however, he worked mainly as a painter and he did not start to concentrate on sculpture until the late 1950s. His work is abstract and has an archaic simplicity and grandeur well suited to the public monuments with which he established a reputation as one of the leading Italian sculptors of the post-war era.
His brother Andrea (1919/20–90) was also a sculptor and often assisted Pietro on his major commissions, notably the Martyrs Monument at Auschwitz in Poland (1958–67). His independent works are smaller in scale than Pietro's and often elegant in form.