European pilchard (Sardina pilchardus, Walbaum, 1792), Golden grey mullet (Liza aurata, Risso 1810), and Common sole (Solea solea, Quensel, 1806) are the commercially important fish species caught by trawl and purse seine in Mersin Bay, in the Mediterranean. This study was aimed to investigate proximate compositions, carbohydrate levels, energy contents, fatty acid profiles, and the lipid quality indexes of European pilchard, Golden grey mullet, and Common sole caught by trawl. The crude protein, lipid, moisture, and ash content were determined as proximate compositions. The protein levels were determined as the highest levels in sardine (24.08%) followed by the common sole (18.91%) and golden grey mullet (18.01%). An inverse correlation between the moisture contents and the lipid levels among the fish was observed in this study. The ash levels, carbohydrate values, and energy contents were in the following order: European pilchard > Golden grey mullet > Common sole. Palmitic acid (C16:0) and oleic acid (C18:1n9) were the highest level of fatty acids in SFA (saturated fatty acids) and MUFA (monounsaturated fatty acids) for the Golden grey mullet and Common sole, respectively. The levels of eicosapentaenoic acid (EPA) in all fish used in this study were found to be different from each other (P<0.05). The amount of docosahexaenoic acid (DHA) were lower than that of EPA in European pilchard and Golden grey mullet. Although the levels of EPA and DHA in fish are found to be in the range of 4.91 - 11.01% and 6.85 - 8.87%, respectively and different from each other, these two fatty acids are good for health.