In the title compound, [Co(C10H12N2O)2(H2O)2](NO3)2·2H2O, the CoII ion, located rab fire rated wafer on an inversion center, is trans-coordinated by two N,O-bidentate chelating (E)-3-(dimethylamino)-1-(2-pyridyl)prop-2-en-1-one ligands and by two water molecules in a slightly distorted octahedral geometry.Intermolecular O—H.O hydrogen bonds link the cations, anions and water molecules into layers parallel to ej10 the ac plane.The crystal packing also exhibits weak intermolecular C—H.O hydrogen bonds.