In the title complex, [Zn(C(12)H(6)O(4))(H(2)O)](n), a Zn(II) polymer based on naphthalene-1,8-dicarboxylate (1,8-nap), the Zn(II) atoms adopt an elongated octahedral coordination geometry. A zigzag chain is formed by mu(2)-aqua ligands and mu(2)-carboxylate groups of the 1,8-nap ligands. Adjacent parallel chains are further linked by 1,8-nap ligands, forming a twisted two-dimensional layer structure along the (100) plane.