Cd(II) and Hg(II) compounds of 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine (Mephtpy) have been synthesized and characterized by CHN elemental analysis, FT-IR, 1H and 13C NMR, thermal analysis and analyzed structurally by X-ray single-crystal diffraction. X-ray analysis showed that the coordination number in complexes were the same with N3I2 coordination sphere. Both metal ions adopt a distorted square-pyramidal geometry. The thermo gravimetric analyses showed that the complexes were stable up to 365 and 340°C, respectively.