Transition metal complexes of Cr(III), Mn(II), Fe(II), Co(II), Ni(II) and Cu(II) metal ions with general stoichiometry [ML2.2H2O] and [ML3], where M= Mn(II), Cr(III), Fe(II), Co(II), Ni(II) and Cu(II), L= Schiff base derived from the condensation of 2-amino-4(4’-phenyl/methylphenyl)-5-methyl-thiazole with 4-acetyl-1(3-chloro phenyl)-3-methyl-2-pyrazoline-5-ones, have been synthesized and structurally characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements and spectral techniques like IR, UV, 1H NMR, 13C NMR and Mass Spectra. All the complexes were found to be octahedral geometry. The ligand and its complexes have been screened for their antifungal and antibacterial activities against three fungi, i.e. Alternaria brassicae, Aspergillus niger and Fesarium oxysporum and two bacteria, i.e. Xanthomonas compestris and Pseudomonas aeruginosa.