The title compound, [Co(C7H6NO2)2(H2O)4] x 4 H2O, contains a Co(II) ion lying on a crystallographic inversion centre. The Co(II) ion is octahedrally coordinated by two 6-methylpyridine-3-carboxylate ligands in axial positions [Co-O = 2.0621 (9) A] and by four water molecules in the equatorial plane [Co-O = 2.1169 (9) and 2.1223 (11) A]. There are also four uncoordinated water molecules. The 6-methylpyridine-3-carboxylate ligands are bound to the Co(II) ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O-H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O-H...O and one of type O-H...N in the packing, resulting in a complex three-dimensional supramolecular structure.