Self-directed learning (SDL) is an educational concept that has received increasing attention in recent years, particularly in the context of higher education. Whilst the benefits of SDL have been espoused by a number of adult education theorists (Brookfield, S., 1986. Understanding and Facilitating Adult Learning. Jossey-Bass, San Francisco; Houle, C., 1984. Patterns of Learning: New Perspectives on Life-Span Education. Jossey-Bass, San Francisco; Knowles, M., 1998. The Adult Leaner: A Neglected Species, fifth ed., Gulf, Houston; Tough, A., 1979. The Adults Learning Project: A Fresh Approach to Theory and Practice in Adult Learning. Ontario Institute for Studies in Education, Toronto), its introduction into curricula has not always been successful (Nolan, J., Nolan, M., 1997a. Self-directed and student-centred learning in nurse education: 1. British Journal of Nursing 6 (1), 51-55; Nolan, J., Nolan, M., 1997b. Self-directed and student-centred learning in nurse education: 2. British Journal of Nursing 6 (2), 103-107; Slevin, O., Lavery, M., 1991. Self-directed learning and student supervision. Nurse Education Today 11, 368-377). The indiscriminate application of SDL principles and poorly prepared teachers and/or students has at times meant that the introduction of SDL has been resented rather than welcomed (Iwasiw, C., 1987. The role of the teacher in self-directed learning. Nurse Education Today 7, 222-227; Turunen, H., Taskinen, H., Voutilainen, U., Tossavainen, K., Sinkkonen, S., 1997. Nursing and social work students' initial orientation towards their studies. Nurse Education Today 17, 67-71). This paper clarifies and explores these issues by: (a) examining the origins of SDL; (b) discussing the relevance of self-directed learning to Knowles' theory of adult learning and contemporary educational practices such as enquiry based learning and problem based learning; and (c) highlighting the implications and limitations of SDL with regard to adult education in general, and undergraduate nursing education in particular.