In The Netherlands, the legal doctrine of informed consent is established in the 'Medical Treatment Contract Act', which was introduced in 1995. This study assessed dental patients' knowledge, attitudes and self-efficacy, as well as their self-reported behaviour concerning informed consent. One hundred and twenty-eight patients (response rate: 91.4%) filled out a questionnaire on these topics, right after their treatment or consultation. Results show that only a minority of the patients is acquainted with the 'Medical Treatment Contract Act'. However, their specific rights concerning informed consent are better known. On the other hand, patients' attitudes and self-efficacy were less positive. Dental patients' self-reported behaviour, did not reflect their attitudes and self-efficacy though. Contrary to social-psychological theory, almost no significant relations were found between the four measured variables, and self-reported behaviour could hardly be predicted by patients' knowledge, attitudes and self-efficacy. In light of these findings, it is concluded that other factors, which take into account more of a consumerist perspective on the dentist-patient relationship, probably play a more important role in predicting to what extent patients assert their rights in dental practice. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.