In 1994 a number of alterations in the Swedish DUI legislation were implemented towards a tougher attitude against DUI-drivers. The legal consequences for driving while intoxicated were sharpened. The limit for heavy DUI was lowered from 1.5 to 1.0 BAC and the maximum penalty was prolonged to two years. The Swedish Prison and Probation Administration decided to start two special prisons for DUI convicted inmates where they should be offered rehabilitation instead of just punishment. An independent evaluation was also decided upon, right from the start. This evaluation is done at the Karolinska Institute in Stockholm. The final evaluation will be based on 804 (82 per cent) convicted DUI´s that were randomized to one of three programs while imprisoned and a comparison group of 176 (18 per cent) not randomized clients. Both groups are to be compared with convicted DUI s in ordinary prisons during the same period. In this article we will present the evaluation project design and some results for the first 333 (34 per cent) clients that were followed up after two years.