Seasonal variations in the fatty acid compositions of gilthead sea bream ( Sparus aurata) and white sea bream (Diplodus sargus), captured in Iskenderun Bay, Eastern Mediterranean of Turkey, were investigated. Results from studying the composition over all seasons showed that the basic saturated, monounsaturated and polyunsaturated fatty acids for gilthead sea bream and white sea bream were palmitic acid ( 16: 0), oleic acid ( 18: 1) and docosahexaenoic acid (DHA, 22: 6w3). The other main fatty acids for both species were myristic acid ( 14: 0), stearic acid ( 18: 0), palmitoleic acid ( 16: 1), linoleic acid ( 18: 2w6) ( especially in autumn and winter for gilthead sea bream), and eicosapentaenoic acid (EPA, 20: 5w3). Gilthead sea bream and white sea bream exhibited seasonal fluctuations in their fatty acid contents. EPA ratios in gilthead sea bream in the autumn, winter, spring and summer were 5.42%, 4.69%, 5.20% and 4.27%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 5.03%, 4.53% and 6.97%, respectively. DHA ratios in gilthead sea bream in autumn, winter, spring and summer were 15.37%, 14.16%, 9.51% and 7.07%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 11.49%, 20.17% and 7.74%, respectively. The present study suggests that the daily consumption of either 100 g of gilthead sea bream captured in any season or 100 g white sea bream captured in spring or summer could meet people's needs for EPA+ DHA fatty acids.