Fatty acid profile and proximate composition of horse mackerel (Trachurus mediterraneus), sole (Solea solea) and black scorpion fish (Scorpaena porcus) caught from the Marmara Sea were determined both in the summer (June-July-August) and winter (December-January-February) seasons. Fish is the best source of omega-3 (omega-3) and contains plenty of omega-6 (omega-6) fatty acids. omega-3 fatty acids provide so many health benefits and help to protect against diseases. In this study, the lipid content of horse mackerel was higher than the other investigated fish species. Total omega-3 and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) of horse mackerel were the highest in summer (1705 mg 100g(-1)) despite having higher lipid content in winter, which could be explained by the nourishment that fish takes in different seasons. Considering the recommended intake, EPA+DHA of horse mackerel was more than enough to meet the daily requirement. The omega-3 content of black scorpion fish and sole were relatively low in comparison with horse mackerel in both seasons. The ratio of omega-6:omega-3 fatty acids of all species was also very low (max. 0.358) which provides advantage in daily nutrition. Docosapentaenoic acid (DPA) and alpha-linolenic acid (ALA) were also found higher in horse mackerel in winter. Instead of taking supplements, fish itself should be consumed to benefit all long chain omega-3 polyunsaturated fatty acids (PUFA) and other nutrients. For a healthy diet, consuming horse mackerel routinely seems to fulfil EPA and DHA needs, besides having high quality protein.