The nickel(II), copper(II), and zinc(II) complexes of the chelated enediols 2,2′-pyridoin and 6,6′-dimethyl-2,2′-pyridoin have been prepared and characterised. They are shown to be co-ordination polymers with minimum molecular weights in the range 2500–3000. The magnetic, spectral, and thermal properties are discussed, and related to the stereochemistry of the metal atom in the complexes.