In the title compound, [Co(C5H7O2)(2)(C13H14N2)(n) or [Co(acac)(2)(dadpm)](n), where acac is acetylacetonate and dadpm is 4,4-methylenedianiline, the Co atom is on a centre of symmetry and is octahedrally coordinated by four O atoms from two acac anions and by two N atoms from two dadpm ligands. Each dadpm ligand, which has a twofold axis passing through its methylene C atom, bridges two Co atoms to form a spiral polymeric chain. Neighbouring chains connect via hydrogen bonds to form a two-dimensional network.