A series of metal complexes of Zn(II) and Hg(II) having the general composition [M(L)(2)]X(2) [where L = 2-formylpyridine thiosemicarbazone; M = Zn(II) and Hg(II); X = Cl(-), NO(3) (-) and 1/2SO(4) (2-)] have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral (IR and mass) studies. The IR spectral data suggests the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for Zn(II) and Hg(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.