Introduction: Earthworms are true coelomates, metamerically segmented annelids. The coelomic fluid of Earthworms is said to have demonstrated antimicrobial activity. Objectives: To study the antimicrobial activity of different concentrations (5 __ampersandsignmu;l, 10 __ampersandsignmu;l, 15 __ampersandsignmu;l, 20 __ampersandsignmu;l/ disc) of coelomic fluid of Earthworm O. suriensis (Octochaetona suriensis) against standard ATCC (American type culture cells /colonies) strains of microbes likeS. aureus (Staphylococcus aureus), E. faecalis (Enterococcus faecalis), E. coli (Escherichia Coli), P. aeruginosa (Pseudomonas aeruginosa) and C. Albicans (Candida albicans). Methods: A standard antibiotic disc of AMP (Ampicillin) 10 __ampersandsignmu;g /disc was used as a positive control for bacteria and KT(Ketoconazole) 10__ampersandsignmu;g/disc for fungi. A plane 6mm Whatman__ampersandsignrsquo;s filter paper disc was used as a negative control on a Petri plate, that was incubated overnight at 37__ampersandsigndeg;C for bacteria and 25__ampersandsigndeg;C for fungi and results were tabulated. Results: The coelomic fluid of O. Suriensis has exhibited excellent antimicrobial activity against all ATCC strains of microbes even at minimum concentrations. In P. aeruginosa it has shown 20mm zone of inhibition at 5__ampersandsignmu;l and at 37 mm zone of inhibition 20 __ampersandsignmu;l, while standard antibiotic Ampicillin did not exhibit any zone of inhibition. In C. albicans it has shown 11mm zone of inhibition at 20__ampersandsignmu;l which is very near to inhibition shown by positive control (ketoconazole 10__ampersandsignmu;g/disc) 12mm. Conclusion: We conclude that coelomic fluid of earthworm O. suriensis is a potent antimicrobial substance. The molecular study should be carried out that may help us to discover new antimicrobial agents.