Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Hastholmen in Loviisa, Kivetty in Aanekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Romuvaara.