In literature as well as in nursing practice a growing concern about nurses' ethical competence can be observed. Based on the cognitive theory of moral development by Kohlberg, this research examined nursing students' ethical behaviour in five nursing dilemmas. Ethical behaviour refers not only to the ethical reasoning of nursing students but also to the relationship between reasoning and behaviour. Kohlberg's definition of morality was refined by adding a care perspective. The results show that the majority of students can be located in the fourth moral stage according to Kohlberg's theory, that is, the conventional level of moral development. This finding implies that students are still guided by professional rules, norms and duties, and have not (yet) succeeded in making personal ethical decisions on the basis of their own principles and acting according to such decisions.