He was consecrated at Rome on 3 May of the same year, on 22 September 1864, was created first bishop of the new Diocese of Gozo, and on the 23rd day of the following month made his entry into the new cathedral.

Through the efforts of Pietro Pace, vicar-general of the diocese, a diocesan seminary was established on the site formerly occupied by the San Giuliano Hospital, the revenues of which were appropriated to the new institution.

On the death of Buttigieg, Paolo Micallef, Superior General of the Augustinian Order, was made Bishop of Città di Castello and appointed administrator of the Diocese of Gozo.

On 12 March 1877, Pietro Pace, native of Gozo, was appointed to succeed Grech Delicata, and was consecrated in Rome by Cardinal Edward Henry Howard.

During this administration an episcopal educational institute for girls was also established, under the care of the Sisters of St. Vincent de Paul, to whom was also entrusted the direction of the annexed orphan asylum.