Seasonal variations in the amino acid and fatty acid compositions of wild sea bass (Dicentrarchus labrax) captured in the north eastern Mediterranean were investigated. In all seasons, the major amino acids in sea bass fillets were determined to be aspartic acid, glutamic acid and lysine. Methionine, tyrosine and histidine composition of the fillets were lower than those of the other amino acids in all seasons. The ratios of essential (E, g amino acid/16 g N)/nonessential (NE, g amino acid/16 g N) amino acids were observed to be 0.75 for winter, 0.76 for autumn, 0.77 for both spring and summer. Results showed that, sea bass fillets are well-balanced food source in terms of E/NE ratios in all seasons. In addition, seasonal differences in polyunsaturated fatty acid (PUFA) composition of the fillets were observed in all seasons. The major fatty acids of sea bass fillets were observed to be palmitic acid (16:0), oleic acid (18:1ω9), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). The amounts of EPA+DHA in autumn, winter, spring and summer were determined as 0.16, 0.12, 1.14 and 1.02 g/100 g wet weight, respectively.