The synthesis, characterization and thermal analysis of mononuclear M(ӀӀ) [M= Mn(II), Co(II), Ni(II), and Pd(II)] or M(ӀⅤ) [M=VO(II) and Pt(IV)] complexes with the ligand namely [N1,N2-bis(3-hydroxyphenyl)oxalamide] (LH2) derived from oxalic acid and 3-aminophenol. Pure complexes of [VO(L2)], [Co(L2)(H2O)2], [Ni(L2)(H2O)2], [Pd(L2)], [Pt(L2)(Cl)(H2O)] have been isolated and characterized by FT-IR, UV-Vis, Mass spectra, 1H-NMR spectra, TGA analysis, chloride containing , molar conductivity and atomic absorption. The spectroscopic data revealed mononuclear complexes and octahedral geometry for each Mn(II), Co(II), Ni(II) and platinum complexes otherwise Palladium complex gave a square planar geometry and Vanadium complex gave a square pyramidal geometry. The biological activities for the new compounds were evaluated against two types of bacteria and fungi and their results were good in inhibition.