The present study was carried out the synthesis of a new mannich base, N-[1-(2-methyl piperidine benzyl)] benzamide (MPBB) and its complexation behaviour with Cu (II), Co (II), Ni (II) and Zn (II) ions. The structural features of the complexes are analysed by elemental analysis, IR, 1H, 13C NMR Spectra. The antimicrobial activity of the ligand and its complexes has been extensively studied in microorganisms such as Staphylococcus aureus, Bacillus substilis, Escherchia coli, Pseudomonas aeroginosa and Fungi Aspergillus niger, Aspergillus fumigatus, Mucor and Candida albicans by disc diffusion method using DMF as solvent. The values of zone of inhibition were found out at 370 for a period of 24 hrs. The complexes have higher antimicrobial effect than the free ligand and the standard.