Dentists and dental students can be exposed to the human immunodeiciency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) during routine work. The aims of this study were to assess a group of dental students' knowledge about HIV, HBV, and HCV infections; assess their attitudes and risk perceptions about the treatment of patients with HIV, HBV, and HCV; and identify factors associated with their knowledge and willingness to treat these patients. An anonymous survey was administered to 534 predoctoral students at the School of Dental Medicine, University of Zagreb, Croatia. The response rate was 71.9 percent. Students' knowledge increased with each year of study. Senior students (in their third, fourth, and ifth years) had more professional attitudes and were signiicantly more positive about dentists' professional obligation to treat patients who are HIV-positive than were junior students (in their irst and second years; p=0.0002). Senior students also expressed signiicantly more willingness to treat intravenous drug users and patients with hepatitis (p=0.016 and p=0.033, respectively). Female students were signiicantly more convinced than male students that routine dental treatment carried a signiicant risk of HIV and hepatitis infection (p=0.025). These students' knowledge negatively correlated with the lack of willingness to treat intravenous drug users and patients with hepatitis, and they expressed their willingness to receive further theoretical and practical education on this topic.