In this article, the contributions of cognitive psychology to research and development of medical education are assessed. The cognitive psychology of learning consists of activation of prior knowledge while processing new information and elaboration on the resulting new knowledge to facilitate storing in long-term memory. This process is limited by the size of working memory. Six interventions based on cognitive theory that facilitate learning and expertise development are discussed: (1) Fostering self-explanation, (2) elaborative discussion, and (3) distributed practice; (4) help with decreasing cognitive load, (5) promoting retrieval practice, and (6) supporting interleaving practice. These interventions contribute in different measure to various instructional methods in use in medical education: problem-based learning, team-based learning, worked examples, mixed practice, serial-cue presentation, and deliberate reflection. The article concludes that systematic research into the applicability of these ideas to the practice of medical education presently is limited and should be intensified.