2-[α-(acetyloxime)ethylidenehydrazino]-4,6-dimethylquinoline (MHQ) and its Cu complexes have been synthesized and characterized by elemental analysis and electronic, vibrational, electron spin resonance and mass spectra. The mononuclear, binuclear and dimeric chelates have been isolated by reaction of the ligand with different CuII salts (nitrate, perchlorate, sulfate, acetate, chloride and bromide)in addition to CuI iodide) in molar ratio 1:1 and 1:2 (metal:ligand). The results showed that the ligand acts as bidante (NN or NO) and tridentate (NNN or NNO). Multilinear regression analysis (MLRA) of the d–d transitions of Cu-MHQ complexes in different solvents vs. Guttmann parameters (AN, DN and ) and solvato parameters (,  and *) have been determined. Full geometrical and structural optimizations of the ligand and its metal complexes have been performed by a PM3 study by using the hyperchem program.