Background: Adolescents are a risk group for acquiring sexually transmitted diseases, including HIV. Correct knowledge about transmission mechanisms is a prerequisite to taking appropriate precautions to avoid infection. This study aimed at assessing the level of HIV-related knowledge among university students as a first step in developing targeted interventions. We used a self-developed HIV knowledge questionnaire, supplemented with socio-demographic and sexual behaviour questions. The questionnaire was composed of 59 items from different existing questionnaires. It included general statements and statements about prevention, transmission and treatment of HIV. Results: There were 357 (79.7%) female and 93 (20.3%) male participants and their median age was 20 (IQR 19-21). On average 42/59 (71.2%) questions were answered correctly, 5 /59 (8.5%) were answered incorrectly and 12/59 (20.3%) were unknown . The best and worse scores were seen on the prevention questions and the treatment questions, respectively. HIV-related knowledge is higher in older students and in students with a health-related education. Students with sexual experience, with five or more partners and students who have been tested on STD’s have a higher HIV-related knowledge. Conclusions: Knowledge on prevention and transmission of HIV is fairly good among university students and knowledge is higher among students with more sexual experience. They still have some misconceptions (e.g. HIV is spread by mosquitoes) and they are ignorant of a substantial number of statements (e.g. risk for infection through oral sex).