Recent environmental constraints and new secure technologies have enforced the development of comprehensive programmes for renewable energy. Wind energy is one of the most promising solutions, especially considering its technological advancements and its growth over the last years. In particular, off-shore wind energy is a key element in the EU White Paper target of 10% contribution of Renewable energy by 2010. In this paper, the technical and economical feasibility of off-shore wind farms is reviewed, in order to evaluate profitability and investment opportunities. In particular, a pre-feasibility study of off-shore wind farms to some selected sites in Puglia Region is provided. The study indicates the best sites in Puglia Region for off-shore plants. For each site, the cost of energy and the profitability of the investment are calculated. Moreover, in the most promising site, different wind turbine generators (WTGs) models are compared in order to evaluate the best performances. In the best site, which presents an average wind speed at 35 m height of 7.66 m/s, the cost of energy ranges between 5.2 and 6.0 cEuro/ kWh. Moreover, the analysis shows that the use of large size WTGs allows reducing the cost of energy and increasing the profitability of the wind farm. (c) 2004 Elsevier Ltd. All rights reserved.