The districts used in the appropriation of members is not coextensive with the
legislative district of Basilan. Unlike congressional representation which is at-large, Basilan is divided into two districts for representation in the Sangguniang Panlalawigan, with the western part of the province (
Isabela City,
Hadji Muhtamad,
Lantawan, and
Maluso) constituting the first district, and the eastern part (
Lamitan City,
Akbar,
Al-Barka,
Hadji Mohammad Ajul,
Sumisip,
Tabuan-Lasa,
Tipo-Tipo,
Tuburan, and
Ungkaya Pukan) forming the second district. Voters in Isabela City, which is administratively separate from Basilan, are allowed to vote for provincial officials, including for 1st district board member. In 2025, the second district gained two additional seats after the
Department of Finance upgraded the province's income classification to 1st class, from 3rd class. ==List of members==