In the title compound, [CoNa(2)(C(7)H(3)NO(4))(2)(H(2)O)(2)](n), the Co(II) atom is coordinated by two pyridine N atoms and four carboxyl-ate O atoms from two doubly deprotonated pyridine-2,6-dicarboxyl-ate ligands in a distorted octa-hedral geometry. One Na(+) cation is coordinated by three carboxyl-ate O atoms and two water mol-ecules and the other is coordinated by five carboxyl-ate O atoms and two water mol-ecules in an irregular geometry. The bis-(pyridine-2,6-dicarboxyl-ato)cobalt complex units are connected by Na(+) cations and bridging water mol-ecules into a three-dimensional coordination network. O-H⋯O hydrogen bonds are formed between the water mol-ecules and the carboxyl-ate O atoms.