All nursing courses in the UK include ethics in the curriculum, although there is considerable variation in the content of ethics courses and the teaching methods used to assist the acquisition of ethical reasoning. The effectiveness of ethics courses continues to be disputed, even when the perceptions and needs of students are taken into account in their design. This longitudinal study, carried out in the UK, but with implications for nurse education in other developed countries, explored the ethical understanding of (...) nursing students and changes in their understanding and approaches to practice over their four years of training (1995-1999). The data collection tools were a questionnaire originally piloted prior to the 1995 study, from which the present study developed, and five vignettes describing ethical dilemmas in health care also piloted in 1995. Students’ thinking progressed as they became more mature as individuals and professionals, although this progress was not necessarily in the direction of greater certainty. Suggestions are made to help nurse educators to maximize the effectiveness of ethics courses in transmitting the skills of ethical reasoning. (shrink)