The purpose of this study was to evaluate the main qualitative traits of European sea bass fattened in farms adopting different rearing techniques (offshore cages, inshore cages, land-based basins) but fed the same diets in each production cycle, in a three year survey (2006, 2007, 2008). Three farms were chosen for each rearing technique and two sampling sessions of ten fish each were carried out for each rearing cycle. The proximate composition, the fatty acid profile and the cholesterol content were evaluated in the fillet of marketable size fish as well as the morpho-biometric parameters and the most important indices. Diets administered in 2008 had higher amounts of lipids, lower proportions of n-3 polyunsaturated fatty acids (PUFA) and higher proportions of n-6 PUFA compared to 2006 and 2007 diets. The chemical and fatty acid composition of the fish fillet was affected by the diet composition: fish fattened in 2008 exhibited statistically higher amounts of fat and cholesterol, lower proportions of n-3 PUFA and higher proportions of n-6 PUFA in comparison with fish cultivated in 2006 and 2007. Fish cultivated in cages, both offshore and inshore cages, exhibited leaner fillets, lower amounts of cholesterol and higher proportions of n-3 PUFA than fish cultivated in basins.