Hydropower has by far been the most mature renevable energy resource used for electricity generation in our planet. Recently, the investors' interest was whipped up by the mas development of small hydropower (SHP) stations, as they are the most prosperous for additional hydropower penetration in developed electricity markets. In Greece, the increasing interest for building SHP stations got off the ground since 1994. Ever since, an enormous number of requests keep piling up in the Greek Regulatory Authority of Energy and the Ministry of Development, with the object of creating new SHP stations of total capacity over 600 MW. The present work is concentrated on the systematic investigation of the techno-economic viability of SHP stations. The study is concluded by a sensitivity analysis properly adapted for the local market financial situation, in order to enlighten the decision makers on the expected profitability of the capital to be invested. According to the results obtained, the predicted internal rate of return (IRR) values are greater than 18% for most SHP cases analysed. Finally, as per the sensitivity analysis carried out, the installation capacity factor, the local market electricity price annual escalation rate and the reduced first installation cost are found to be the parameters that mostly affect the viability of similar ventures. (c) 2004 Elsevier Ltd. All rights reserved.