Problem-based learning arose out of educational initiatives in the 1960s and is often one of the most contentious issues within medical education. McMaster University in Canada was the first to implement problem-based learning on a large scale within medicine and this was soon followed by universities in Europe and Australia. In modern times, few western medical schools do not include at least some aspect of problem-based learning within their instructional itinerary, and many build their entire curriculum and instructional procedures around problem-based learning. This article provides an overview of problem-based learning within medical education, pertinent background, describes the characteristics of problem-based learning, its advantages and disadvantages, problem-based learning scenarios and facilitation.