The present study was designed to evaluate the antimicrobial efficacy of Mitragyna parvifolia (barks) and Butea monosperma (leaves) against human pathogenic microbial strains such as two Gram positive (Staphylococcus epidermidis, Bacillus subtilis), two Gram negative (Escherichia coli, Pseudomonas aeruginosa) and two yeasts (Saccharomyces cereviseae, Candida albicans) assayed by using agar well diffusion assay. Three different extracts (ethanol, methanol and water) of each plant were used during the study. M. parvifolia extracts showed better activity than the B. monosperma extracts. The zone of inhibition in M. parvifolia extracts (ethanolic and methanolic) was in the range of 14mm to 25mm and 10mm to 14mm in case of B. monosperma extracts. The aqueous extracts did not show any inhibitory activity against any of the test bacterial strains. No antifungal activity was observed against the test yeast strains. The MIC values of methanol extract of Mitragyna parvifolia for different bacterial strains ranged from 6.25mg/ml to 12.5mg/ml. On the basis of this finding, the extracts demonstrating antimicrobial efficacy could result in the discovery of novel antimicrobial agents.