Born on November 15, 1914 in Lapio in the archdiocese of Benevento, Caprio was ordained priest on December 17, 1938. He was then called upon to work in the Vatican's diplomatic service.

In 1947, he became secretary of the Nunciature to China, remaining in the country until new political circumstances required him to leave. He was next in Brussels, then Saigon, and in 1959 he was named Nuncio to Taipei (Taiwan).

He was made Archbishop of Apollonia on October 14, 1961; in 1967, Pro-Nuncio to Delhi; and on April 19, 1969, became Secretary to the Administration of the Patrimony of the Holy See (APSA). On June 14, 1977, Paul VI named him deputy Secretary of State. He was elevated to the College of Cardinals by John Paul II at the Consistory of June 30, 1979.

Caprio was Grand Master of the Equestrian Order of the Holy Sepulchre of Jerusalem (EOHSJ). Until 1989, he was President of the Prefecture for the Economic Affairs of the Holy See.

HE Giuseppe Cardinal Caprio with the insignia of the Grand Master of the Equestrian Order of the Holy Sepulchre of Jerusalem