To study antimicrobial activity of shallot in comparison with that of garlic and onion against 23 strain and bacteria, water extracts of garlic, shallot and onion bulbs were prepared. Each extract was studied in different forms for their antimicrobial activity viz. fresh extract, dry extract and autoclaved extract. Minimal inhibitory concentration and minimal lethal concentrations of these extract were determind against all organisms by broth dilution susceptibility test. Fresh extract of garlic showed greater antimicrobial activity as compared to similar extract of onion and shallot. However, dried and autoclaved extract of shallot showed more activity than similar extract of onion and garlic. Fungi were more sensitive to shallot extract than bacteria. Amongst bacteria. B. cereun was most sensitive (MIC=5 mg ml) The lowest minmum bactericidal concentration of shallot extract amongst bacteria tested was 5 mg ml for B. cereun. Amongst fungi, Aureobasidium pullulans and Microsporum gypseum were most sensitive (MIC=0.15 mg ml).The lowest minimum lethal concentration was 2.5 mg ml for Microsporum gypseum and Trichophyton mentagrophytes. It was therefore, expected that the antimicrobial principle of shallot was different than the antimicrobial compounds of onion and garlic. In addition,the antimicrobial compounds of the shallot extract was stable at 121 c