He was appointed Auxiliary Archbishop of the Archdiocese of Malta (then to Coadjutor Archbishop in 1968) and Titular Bishop of Nomentum on 15 February 1967 and was consecrated on 18 June 1967. A former priest-secretary recalled at the time of his death that one of the Gerada's achievements was an improvement in the relations between the Maltese Church and the Labour party, Such was the deterioration in the relationships that Catholic Labour supporters were denied burial in the blessed part of cemeteries and voting Labour was declared a mortal sin. But Gerada negotiated an agreement acceptable to both sides.
Gerada resumed his diplomatic career with the Holy See in 1973 when he appointed Apostolic Nuncio to El Salvador and Guatemala. In this post he was said to lobby for the appointment of Archbishop Oscar Romero but later the two men would clash when Romero cancelled many Sunday masses after the state-sponsored murder of Jesuit priest Fr Rutilio Grande in 1977.
On 15 October 1980 he was appointed Apostolic Pro-Nuncio to Pakistan and served until his appointment as Apostolic Nuncio to Ireland on 4 February 1989. His arrival in Ireland was greeted warmly coming after the rather austere and conservative Archbishop Gaetano Alibrandi. Gerada was the Vatican's man on the ground when Rome attempted to silence Bishop Brendan Comiskey over his views on celibacy but otherwise his time as Nuncio was lived out of the public eye as the full storm over child sexual abuse and episcopal cover-up had yet to occur. Though claims were made that a priest with suspicions about the deviant behaviour of Fr Brendan Smyth did write to Archbishop Gerada.
Gerada retired on 17 October 1995 and died on 21 January 2011.