Aqua cultured fish (sea bream) were irradiated by Cobalt-60 at commercial irradiation facility at dose of 2.5 and 5 kGy at 2-4 degrees C. The proximate composition, fatty acid and amino acid composition changes of irradiated aqua cultured sea bream (Sparus aurata) of Aegean Sea were investigated. Total saturated (28.01 %) and total monounsaturated (28.42%) fatty acid contents of non-irradiated decreased content of 27.69-27.97% for 2.5 kGy irradiated groups and increased content of 28.33-28.56% for 5 kGy irradiated groups after irradiation process. Total polyunsaturated fatty acid content for irradiated samples was lower than that of non-irradiated samples. Aspartic acid, glutamic acid, serine, glycine, arginine, alanine, tyrosine, cystine, tryptophan, lysine and proline contents for 2.5 and 5 kGy irradiated sea bream are significantly different (p < 0.05). (c) 2007 Elsevier Ltd. All rights reserved.