14 species of cyanobacteria belongs to 10 genera were isolated and identified from Athirampattinam coastal area of Tamil Nadu coast. Among this, Oscillatoria princeps and Lyngbya majuscula were the dominant group selected for the present study. The antimicrobial activity of Oscillatoria princeps and Lyngbya majuscula was maintained by using different solvents viz. ethanol, acetone, methanol and water. The Oscillatoria princeps and Lyngbya majuscula were tested against human pathogens like Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Aspergillus niger and Candida albicans to know the antimicrobial activity. The present study shows maximum antimicrobial activity was reported in ethanol extracts of cyanobacterial species. The ethanol extract of Oscillatoria princeps showed maximum inhibition against all the human pathogens than Lyngbya majuscula. Similarly bacterial pathogens were showed maximum inhibition when compared to fungal pathogens.