The lipid content and the fatty acid composition of the fillets of the six fishes burriqueta (Menticirrhus americanus), white croaker (Micropogonias furnieri), black drum (Pogonias cromis), Brazilian menhaden (Brevoortua spp.), pampano (Parona signata), and king weakfish (Microdon ancylodon) of the RıB o de la Plata in Uruguay were analyzed and evaluated as sources of polyunsaturated fatty acids in comparison with fish oil capsules and hake (Merluccius hubbsi) liver oil. The lipid content of the fish fillets was found to vary over a wide range (0.56 to 13.6 g/100 g fillet), while the protein level varied very little (19.2 to 20.7 g/100g fillet). The percentage of docosahexaenoic acid (DHA) exceeded that of the eicosapentaenoic acid (EPA) in all the fish species analyzed. The actual content of these acids in the fillets indicated that Brazilian menhaden, burriqueta, and pampano provide the recommended daily intake of 1 g of EPA / DHA with reasonable amounts of fillet. The energy input for a daily gram intake of EPA / DHA provided by fish fillets ranged from 300 kJ for fatty fishes to more than 3000 kJ for lean fishes. For the same dose of EPA / DHA, the energy input provided by fish oil capsules is less than 250 kJ. Hake liver oil is a rich source of polyunsaturated fatty acids and a potential raw material for the production of fish oil capsules.