It is well known that fish lipids are effective against cardiovascular diseases due to their high contents of polyunsaturated omega-3 (n-3) fatty acids. In order to determine a suitable fish diet, the fatty acid compositions and total lipid and cholesterol contents of 9 common fish species obtained from the central fish market in Istanbul were determined. Palmitic (C-16:0) and oleic acid (C-18:1) were the predominant saturated and monounsaturated fatty acids. The predominant polyunsaturated fatty acids were eicosapentaenoic (C-20:5) acid and docosahexaenoic (C-22:6) acid. The amounts of cholesterol in fish lipids did not differ significantly. Sardine (Sardina pilchardus) and mackerel (Scomber scombrus) were found to be the most suitable pelagic species for a preventive diet. Of the groundfishes, only red mullet (Mullus surmuletus) were found to be suitable.