The objective of this paper was to describe cage rearing of small bluefin tuna (Thunnus thynnus L.) in the Adriatic Sea. Approximately 6200 fish, captured by purse seine, were stocked in a 50 m diameter cage. After two weeks of acclimatisation, tunas were fed raw, defrosted small pelagic fish, dominated by herrings. Feeding experiment was from July-October 1999. Feed was distributed by hand six days per week, twice a day. Tunas were daily fed with the quantity of food equal to 5.1 percent of their biomass at a temperature from 18 to 24 degrees C and the oxygen saturation was above 90 percent. The highest mortality rate (2.1 per cent) was noticed during the first month of adaptation, while in the following months it was significantly lower (0.6 percent). Some specimens were measured and tagged, with the aim of estimating their daily growth rate over a 540 day rearing period.