The Diocese of San Jose, Nueva Ecija, was created on Feb. 16, 1984 by Pope John Paul II and canonically erected on July 14, 1984. Its territory was taken from the Diocese of Cabanatuan which at same time of the division comprised the entire province of Nueva Ecija.
Sixteen parishes, out of forty one parishes of the Diocese of Cabanatuan were adjudicated to the Diocese of San Jose, Nueva Ecija. 80 percent of the people are Roman Catholics and the rest of 20 percent are members of different sects and denominations.
Bishop Florentino F. Cinense, DD, was appointed the diocese's first diocesan bishop on July 14, 1984. When appointed coadjutor bishop of Tarlac, he remained as Apostolic Administrator of San Jose, until the appointment of his successor Bishop Leo M. Drona, SDB, DD, on July 25, 1987. Bishop Leo M. Drona had been a Salesian of Don Bosco for twenty nine-years prior to his Episcopal appointment. He is the first Filipino Salesian priest as well as the first Filipino Salesian Bishop. In June 2004, Bishop Drona was transferred to the Diocese of San Pablo, Laguna as its third bishop. He was succeeded by Bishop Mylo Hubert C. Vergara who was installed as the third bishop of the Diocese of San Jose de Nueva Ecija on May 14, 2005. Then Bishop Mylo C Vergara transferred to the Diocese of Pasig. It was May 15 when Pope Benedict XVI named the current Bishop Roberto C. Mallari.