[1] On May 27, 1951, Casullo was appointed the Bishop of Nusco and was ordained to the episcopate on July 15, 1951, in the Ariano Irpino Cathedral.

"[1] Casullo served as a Conciliar Father in all four sessions of the Second Vatican Council,[2] where he insisted on the role of missionary work.

[2] Casullo left Italy for Brazil on May 12 of that year, stopping at the Sanctuary of Fátima in Portugal along the way, and arriving in Rio de Janeiro on May 17.

[2] Having reached the retirement age of 75, Casullo submitted his resignation to the Pope on November 5, 1985, and assumed emeritus status in the diocese.

[1] On January 10, 2004, Casullo died at the Hospital Gastroclínica in Fortaleza, Brazil, of a heart attack at the age of 94.