Problem-based learning (PBL) is a philosophy and teaching method that structures knowledge in clinical contexts, strengthens motivation to learn, develops clinical reasoning skills, and enhances self-directed and life-long learning. During the past 30 years, PBL has been implemented in schools of medicine worldwide, including 100 of the 126 schools in the United States. This article reviews the international PBL literature and focuses on the key aspects of this paradigm in educating health professionals: recent history and worldwide diffusion, basic characteristics and rationale, typical case presentation, student and tutor roles, and data-based outcomes. Conclusions from selected meta-analytic studies of assessment are described and discussed. The potential of PBL for nursing education is examined. Key implementation issues are identified, including the challenge to persuade faculty to move from efficient teaching to effective learning.