The analytical composition and nutritional value of market size eel, rainbow trout, sea bass and sea bream fillets from intensive Italian fish farms were determined. The lipid content (4.08% on fresh flesh for rainbow trout, 6.81% for sea bream, 7.62% for sea bass, 27.19 and 30.57% for eels of 700 an 200 g, respectively) was higher than data reported in the literature for the Italian situation (0.1 - 3.0% for sea bass, 0.2 - 5.9 for sea bream, 18.7 - 25.6 for eels, higher variability for trout 2.1 - 14 on fresh flesh), which generally are referred to wild fish. The atherogenic (A.I.) and thrombogenic (T.I.) indices were very good (A.I., from 0.48 to 0.54; T.I., from 0.23 to 0.42). Fish, particularly eel, were rich in oleic acid, C18:1 (n-9), (from 18.2 to 29%), and in (n-6)PUFA and in (n-3)PUFA, mainly in marine fish. The quality of protein was high in all fish species. Analytical results confirmed the high nutritional value of reared fish meat, the higher lipid content in reared fish compared to wild ones must however be considered in dietetic regimes because of the higher energy content of the fish flesh, and in fish processing to avoid alterations in the sensorial, compositional and nutritional quality of the product.