Aegle marmelos is a medicinal herb belongs to the family Rutaceae, used for antimicrobial screening against selected four pathogenic microorganisms - Escherichia coli MTCC40, Salmonella typhi MTCC3216, Proteus vulgaris MTCC428 & Staphylococcus aureus MTCC3160. Bark of Aegle marmelos was extracted in ethanol and petroleum ether through cold and hot extraction method. For control petroleum ether, ethanol and Ampicilin were used.