The diocese comprises 16 towns of Nueva Ecija including the cities of Cabanatuan, Palayan, and Gapan.

[2] On February 16, 1963 Pope John XXIII, issued the apostolic letter "Exterior Ecclesiae" creating the Diocese of Cabanatuan in Nueva Ecija separating from the Archdiocese of Lingayen-Dagupan, and then the Diocese of San Fernando.

The Diocese of Cabanatuan was put under the patronage of Saint Nicholas of Tolentino and the Virgin Mary under the title Divine Shepherdess (Divina Pastora) which is popularly venerated in Gapan every May 1.

The seat of the diocese is the St. Nicholas of Tolentino Cathedral in Cabanatuan with a feast day of September 10.

The current bishop Emeritus of the diocese and Apostolic administrator is Sofronio Aguirre Bancud, S.S.S., D.D.