Problem-based learning (PBL) in medical education uses clinical cases as the context for students to study basic and clinical sciences. Its possible advantages over traditional approaches include its greater relevance to the practice of medicine, its ability to promote retention and application of knowledge, and its encouragement of self-directed life-long learning. Possible disadvantages include higher costs, both in resources and staff time. Although its efficacy is difficult to evaluate, the current enthusiasm for PBL seems justified and its use is likely to increase further.