The principle objective of this study was to investigate the presence of antimicrobial activities in the larvae of insect Musca domestica (house fly). For this purpose, the body wall of the insect larvae were injured by a sterile hypodermic needle and then the larval extract were prepared in acidic (pH 5.0), neutral (pH 7.0) and alkaline (pH 8.0) buffers or water. These extracts were used for the screening of antimicrobial activities against 11 bacteria and 10 fungi by an agar disc diffusion assay and by poisoned food technique respectively. All the three extracts showed inhibition against 2 bacterial species viz.,__ampersandsignnbsp;Salmonela typhi, Bacillus subtilis and 5 fungi viz., Macrophomia phaseolina , Fusarium equiseti , Colletrotrichum corchori, Alternaria alternate and Rhizopus species. The acidic extract also showed__ampersandsignnbsp;inhibition against bacteria Escherichia coli. Of the three extracts, acidic extract showed highest__ampersandsignnbsp;inhibition against all the microbes. Cytotoxic activity (LC50) of the acidic, neutral and alkaline extract was found to be 141.2 __ampersandsignmu;g/ml, 152.2 __ampersandsignmu;g/ml and 149.5 __ampersandsignmu;g/ml respectively.