Eviscerated sea bass, Dicentrarchus labrax were irradiated by Cobalt-60 at commercial irradiation facility at dose of 2.5 and 5 kGy at 2–4°C. The influences of the irradiation on proximate, fatty acid and amino acid composition in cultured sea bass were investigated. Significant differences (P<0.0.5) were found between non-irradiated and irradiated sea bass in terms of moisture, protein, fat, ash and carbohydrate contents. Total saturated and total monounsaturated fatty acid contents were 27.97-24.72% for non-irradiated sea bass respectively. The amonts of these two fatty acids in irradiated samples increased to 28.18-25.75% for 2.5 kGy and 29.08-28.54% for 5 kGy. Total polyunsaturated fatty acid content for irradiated samples was higher than non- irradiated samples. Aspartic acid, glutamic acid, asparagines, histidine, serine, glycine, arginine, alanine, tyrosine, cystine, methionine, lysine, hydroxyproline and proline contents for 2.5 and 5 kGy irradiated sea bass were significantly different (P<0.05).