The province is currently represented in the lower house of the Congress of the Philippines through its first, second, third, and fourth congressional districts.
During the Japanese occupation of the Philippines in the Second World War, two delegates represented Nueva Ecija in the unicameral National Assembly of the Second Philippine Republic: one was the provincial governor (an ex officio member), while the other was indirectly elected through local conventions of KALIBAPI party members.
[3] The pre-war two-representative district configuration was restored upon the re-establishment of the Philippine Commonwealth in 1945, and lasted until the disbandment of Congress in 1972 as a result of the declaration of Martial Law.
Two chartered cities created during this period — Cabanatuan (1950) and Palayan (1965) — remained part of the second congressional district of Nueva Ecija, by virtue of Republic Act No.
The province was reapportioned into four congressional districts[6] under the new Constitution which was proclaimed on February 11, 1987, and elected members to the restored House of Representatives starting that same year.