The two filamentous marine cyanobacteria Phormidium tenue (Phormidiaceae) and Lyngbya sp. (Oscillatoriaceae) were isolated from central west coast of India and were analyzed for their biochemical composition including nutritionally important protein, carbohydrate, lipid and fatty acids composition. Both cyanobacteria had moderately high protein, lipid and other biochemical components, which were comparable to other nutritionally rich microalgae. There were four major fatty acids: palmitic acid (PA, 36.6, 20.9%), carpric acid (CA, 15.5, 14.0%), oleic acid (OA, 5.7, 10.1%) and stearic acid (SA, 12.6, 10.7%). Saturated fatty acids predominated (SFA, 85.7, 76.6%), followed by monounsaturated fraction (MUFA, 8.0, 15.9%) and polyunsaturated acids (PUFA, 6.3, 7.4%). Thus, Phormidium tenue and Lyngbya sp. have essential constituents of nutritional and medicinal value for its use in dietary and pharmaceutical applications.