This study sought to determine the level of general knowledge about HIV infection among Finnish medical students and their willingness to participate in AIDS vaccine trials. One hundred and sixty-two volunteer medical students at the University of Kuopio in the 2nd and 5th years of training filled self-administered questionnaires. The overall response rate among the 2nd year students was 77%, and among the 5th year students 70%. Knowledge was scored on a percentage scale. The mean score on general knowledge about HIV among 2nd year students was 75.6 (SD=0.23) while in the 5th year it was 87.8 (SD 0.18). Fifty-four students (77%) from the 5th year and 66 (72%) from the 2nd year indicated their willingness to participate (WTP) in AIDS vaccine trials (p=0.09). Medical curricula should be constantly revised to keep medical students up-to-date about recent advances in HIV/AIDS research.