In the present work, we synthesized new thiosemicarbazone based Schiff base ligands and their Mn(II), Ni(II), Cu(II) and Zn(II) complexes. The synthesized compounds were characterized and their antimicrobial activities were studied. Elemental analysis, IR, ¹H-NMR and mass spectrometry were done to fully characterize all the compounds. The ligands and their complexes were screened for in-vitro biological study against Gram positive (Bacillus subtilis) and Gram negative (E. coli, Klebsiella pneumonia, Pseudomonas aeruginosa) bacteria for the Zone of Inhibition method. The thiosemicarbazone based complexes showed better activity than the ligands.