4-Formylpyridine N(4)-methylthiosemicarbazone (H4FP4MT) was synthesized and characterized by LC-MS, IR, UV-visible, 1H NMR, and 13C NMR spectra. Equilibrium studies of H4FP4MT were carried in 70%v/v DMF-Water medium. Proton dissociation constant of H4FP4MT and the stability constants of Zn(II) and Cd(II) complexes with H4FP4MT were determined pH metrically. Metal complexes, MLn of H4FP4MT(L) with Zn(II), Cd(II) and Hg(II) were prepared and characterized by various spectro-analytical techniques such as elemental analyses, molar conductance, LC-MS, TGA, IR and 1H-NMR. Elemental analyses, LC-MS and TGA studies reveal the composition of the complexes as ML2 for all the complexes. Antibacterial activity of H4FP4MT and its metal complexes against gram positive and gram negative bacterial strains were studied and found to be active.