The demands of physician practice are growing. Some specialties face critical shortages and a significant percentage of physicians are aging. To improve health care it is paramount to understand and address challenges, including cognitive issues, facing aging physicians. In this article, we outline several issues related to cognitive performance and potential implications associated with aging. We discuss important findings from other fields and draw parallels to the practice of medicine. In particular, we discuss the possible effects of aging through the lens of situated cognition theory, and we outline the potential impact of aging on expertise, information processing, neurobiology, intelligence, and self-regulated learning. We believe that work done in related fields can provide a better understanding of physician aging and cognition, and thus can inform more effective approaches to continuous professional development and lifelong learning in medicine. We conclude with implications for the health care system and areas of future research. (Contains 1 figure.)