The members are elected via plurality-at-large voting: the province is divided into six districts, each having two seats.

A voter votes up to two names, with the top two candidates per district being elected.

The vice governor is the ex officio presiding officer, and only votes to break ties.

Aside from the regular members, the board also includes the provincial federation presidents of the Liga ng mga Barangay (ABC, from its old name "Association of Barangay Captains"), the Sangguniang Kabataan (SK, youth councils) and the Philippine Councilors League (PCL).

Isabela's provincial board also has reserved seats for the sectoral representatives for women, labor, and indigenous people.