This article describe the syntheses and characterization of some new diorganosilicon(IV) and diorganotin(IV) complexes having general formulae R2MCl(L1) (1a, 1b), R2M(L1)2 (1c, 1d) R2MCl(L2) (2a, 2b), and R2M(L2)2 (2c, 2d). The compounds were synthesized from the reaction of R2MCl2 with new Schiff bases (HL1-2) in 1 : 1 and 1 : 2 molar ratios, where M=Si and Sn, R=CH3. The Schiff bases HL1 and HL2 have been prepared by the reaction of 3-bromobenzaldehyde with 4-amino-5-mercapto-s-triazole and 4-amino-5-mercapto-3-methyl-s-triazole, respectively. The new Schiff bases and their metal complexes have been characterized by elemental analysis, molar conductance and spectroscopic studies including UV, IR, 1H, 13C, 29Si and 119Sn NMR spectroscopy. On the bases of these studies, the resulting complexes are proposed to have trigonal bipyramidal (compounds 1–4) and octahedral geometries (compounds 5–8). In vitro activities of ligands and their metal complexes against some Gram positive (Staphylococcus aureus and Bacillus subtilis), Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and fungi (Aspergillus Niger and A. Flavus) have been carried out. The antimicrobial data reveals that the organometallic compounds are superior to the free ligands and their toxicity has increased as per the increase in concentration.