New tetrakis(2-pyridonato)copper(II)-palladium(II) /platinum(II) complexes, [CuPd(2-pyrd)(4)(py)] (1), [CuPt(2-pyrd)(4)(py)] (2), [CuPd(2-pyrd)(4)(H2O)] (3), and [CuPt(2-pyrd)(4)(H2O)] (4) (2-pyrd = 2-pyridone, py = pyridine), were prepared, and the metal-metal bonds between Pt-II/Pd-II and Cu-II atoms were evidenced on the basis of X-ray structural and ESR spectroscopic methods, which were also supported from the DFT calculations.