New Ni(II), Cu(II) and Zn(II) complexes have been synthesized by reaction of a terdentate Schiff base ligand 1-[N- (5-chloro-2-hydroxyphenyl)imino]methyl}-2-naphthol (H2L) with metal(II) acetates. The synthesized complexes have been characterized by elemental analyses, IR, UV-Vis and 1H NMR spectroscopy. The thermal behaviors of complexes have been investigated by TGA and DTA. In all complexes the Schiff base acts as a terdentate ligand and coordinates to the metal via two phenolic oxygen and azomethine nitrogen.