In the title mononuclear complex, [Co(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, the Co(II) atom exhibits a distorted octa-hedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxyl-ate ligand and five water O atoms. A supra-molecular network is generated through inter-molecular O-H⋯O hydrogen-bonding inter-actions involving the coordinated and uncoordinated water mol-ecules and the carboxyl O atoms of the organic ligand. An inter-molecular N-H⋯O hydrogen bond is also observed.