Cyanobacteria as proven source of bioactive secondary metabolites have recently found immense application in pharmaceutical sector. The goal of this study was to find out the antimicrobial property in two species of cyanobacteria, Oscillatoria boryana and Oscillatoria pseudogeminata against different pathogenic microorganisms. Aqueous and different solvent extracts (acetone, methanol, benzene) were prepared and assayed for antimicrobial activity against four bacterial (Staphylococcus aureus, Bacillus subtilis, Vibrio cholerae and Eschercichia coli) and four fungal (Aspergillus niger, Candida albicans, Penicillium verrucosun and Fusarium oxysporum) pathogens. The study results recorded highest antimicrobial activity in methanol extracts of O. boryana showing significant zone of inhibition against V. cholerae (20±0.74 mm) and C. albicans (17±0.80 mm). Least antimicrobial activity was detected in aqueous extract among all the test species. The purified active fractions were analysed using GC-MS, where dominant compounds that are responsible for the inhibitory activity such as n-hexadecanoic (15.42%) 5-Methyl-2-phenyl indolizine (13.3%), Acetic acid (12.47), 5-Nitro-3-cyano-2(1H)-pyridone (10.37 %), 9-Oxo-9,10-dihydro acridine-4-yl (6.8%) were detected.Thus the obtained results suggests that studied species of cyanobacteria can be prospective in biotechnology as an alternative sources of antimicrobial substances.