Compounds of benzylmalonic acid with cobalt, nickel and copper have been prepared in aqueous solution. The compounds have stoichiometry Co(C10H8O4) . 2H2O; Ni(C10H8O4) . 3H2O and Cu(C10H8O4). The cobalt and nickel complexes have octahedral structures, and the copper complex has a tetragonal structure. Thermal decomposition studies show that the cobalt and nickel complexes decompose with the loss of water followed by the organic ligand to give the metal oxides. The copper compound loses organic ligand to give copper oxide.