Prior to the establishment as a local church, the present-day Diocese of Pasig used to be a part of the Archdiocese of Manila (largely under the Ecclesiastical District of Makati).

The oldest parishes, built during the Spanish colonialization period, were in Pasig (Immaculate Conception), Pateros (San Roque), and Taguig (Saint Anne).

The northeastern side of Pasig, which comprises the barangays of Manggahan, Santolan, De La Paz, Santa Lucia, and Rosario, was given to the newly established Diocese of Antipolo in 1983.

Parishes belonging to the Vicariate of the Immaculate Conception and to the municipalities of Taguig and Pateros were part of the Ecclesiastical District of Makati, which was then headed by Manila Auxiliary Bishop Crisostomo Yalung.

The bishop named Ramil Marcos, his private secretary and vice-chancellor, as the second vicar general of the diocese and Roy Rosales as the fourth rector of the cathedral.

His term was marked by the papal canonical coronation of the image of Our Lady of the Immaculate Conception of Pasig in the cathedral on December 7, 2008, the solemn declaration of San Roque Parish in Pateros as the Diocesan Shrine of Santa Marta on February 7, 2009, and the establishment of Tanyag Chapel, which belonged to Sagrada Familia Parish, as a quasi-parish (Our Mother of Perpetual Help Quasi-Parish) on September 8, 2010.

On December 21, 2010, Pope Benedict XVI accepted San Diego's retirement as bishop and named Manila Archbishop Cardinal Gaudencio Rosales as concurrent apostolic administrator of the diocese.

During his term, Bishop Vergara strengthened the lay evangelization programs in the diocese, invited some religious orders to administer a number of parishes in the diocese, and oversaw the inauguration of the Tahanan ng Mabuting Pastol (House of Good Shepherd) Building within the vicinity of Santa Clara de Montefalco Parish to house the new bishop's residence and diocesan offices on April 24, 2017.

Daniel L. Estacio (Resident Priest) The Diocese of Pasig had 1,306,505 baptized Catholics, representing 82.7 percent of all 1,580,225 people in the territory (as of March 2008).