ABSTRACT By condensing ethylene-1,2-diamine with different aldehydes such as benzaldehyde, 4-chloroacetophenone and 2-chlorobenzaldeyhde within 1:2 molar ratio, resulted new series of Schiff base ligands (L1)-(L3) containing bidentate nitrogen atom. Their metal complexes were synthesized by coordinating the ligands with transition metals as Co(II), Cu(II), Ni(II) and Zn(II) and exhibited octahedral geometry. Their characterization was done with the help of spectral, physical and analytical analysis. Spectral and elemental analysis of all bidentate ligands and their corresponding 3d-metal chelates was consistent with their proposed structures, signifying the high purity of these compounds. For in-vitro studies, these metal complexes along their ligands were screened against the six bacterial strains; Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Streptococcus faecalis. Six fungal strains; Aspergillus niger, Trichophyton mentogrophytes, Epidermophyton floccosum, Trichophyton schoenleinii, Microscopum canis and Fusarium culmorum were used to study antifungal activity of the compounds. Bioactivity results exhibited that metal complexes showed higher antimicrobial potential as compared with their corresponding ligands. The enhanced activity resulted due to chelation that decreases the polarity of metal ions by complexing with bidentate ligands.