The title compound, [Co2(C7H4NO4)2(C10H8N2)2(H2O)4](C7H4NO4)2, consists of a centrosymmetric bimetallic complex charge-balanced by free 4-nitrobenzoate anions. The CoII ion exhibits a distorted cis-CoN2O4 octahedral coordination environment and the Co...Co separation is 3.326 (2) Å. In the crystal, the dications and anions are linked by O—H...O and C—H...O hydrogen bonds.