ObjectiveTo study antimicrobial activity of some potential green algal strains viz., Scenedesmus abundans, Nannochloropsis oculata and Spirogyra condensata, against four human bacterial pethogens. MethodsThe characterization of the antimicrobial activity was used disc diffusion method against four human pathogenic bacteria viz., Escherichia coli, Staphylococcus aereus, Bacillus cereus and Pseudomonas aerugenosa.Streptomycin disc were used as a positive control and only solvent were used as a negative control. ResultsThe methanolic extract of Scenedesmus abundans, Nannochloropsis oculata, and Spirogyra condensata showed