A new coordination polymer, {[Co-II(imbz)(2)].H2O}(n) [imbz(-) = 4'-(imidazol-1-ylmethyl)benzoate anion] was synthesized and characterized by X-ray crystallography. Each Co(II) atom is coordinated by four imbz ligands, two of which using N atoms of imidazole and the other two using O atoms of benzoate, and each imbz ligand connects two Co(II) to generate an infinite 2D network. The crystal water molecules locate in the voids of two adjacent layers through C-H---O and O-H---O hydrogen bonds.