The growth rate, survival, and feeding parameters of Mediterranean amberjack (Seriola dumerili Risso, 1810) cultivated in offshore cages in the Gulf of Iskenderun (Hatay, Turkey) were investigated from July 2006 to March 2008. Two offshore cages (339 m(3)) were placed at a depth of 10 m in a sheltered area 500 m off the coast. Juveniles (101.97 +/- 14.54 g), caught with seine nets 400-1200 m from the coast, were stocked in the cages at 250 per cage. Fish in one cage, Group A, were fed commercial pellets for all 20 months whilst fish in the second cage, Group B, were fed pellets for the first 16 months and frozen sardines for the following four. The mean live weight, survival, feed conversion ratio, daily feed consumption, and water quality parameters were recorded monthly. Group B reached a significantly (p < 0.05) greater weight (2785.00 +/- 64.91 g) than Group A (2441.14 +/- 38.13 g). Food conversion ratios ranged 1.16-2.46 for group A and 1.10-2.28 for group B, low when compared with other studies on amberjacks in the Mediterranean. Average mortality was 25%, due to a Zeuxapta seriolae (Monogenea: Heteraxinidae) infection in December 2006 (20%) and fish handling for measurement in June 2007 (similar to 5%). The farmed amberjacks had significantly higher protein and lipid contents than their wild counterparts at the end of the 20-month feeding period. Amberjacks found frozen sardines more appealing than pellets, especially during the winter. In conclusion, it is advised to feed Mediterranean amberjack frozen sardines or other trash fish during the winter grow-out period. Their rapid growth rate, as well as their adaptability to farming, make offshore net cages a promising system for the aquaculture of this species.