Never upset a pediatrician. They have very little patients. Egerton Yorick Davis It is often said that laughter is the best medicine (not true, it’s actually amoxicillin). But how often do we consider the power of laughter or, more broadly, the role of humor in our teaching of medicine? When executed well, humor can increase learner engagement and participation, cultivate relationships, foster an effective learning environment, and increase satisfaction during teaching encounters.1,2 It may also calm students’ anxieties and result in a more approachable dynamic between learner and instructor.3 There is some, albeit weak, evidence that humor can lead to improved learning, particularly if that humor is directly relevant to the topic.2 There is also evidence that the prudent use of the right kind of humor can increase engagement and participation during university lectures.1 Overall, humor is identified as a key contributor to teaching effectiveness. This article continues the series by the Council on Medical Student Education in Pediatrics by exploring the role humor plays in medical education. Humor is defined as a funny or amusing quality, whereas a sense of humor is defined as the ability to be funny or to be amused by things that are funny. Despite the seemingly innocuous nature of humor, historically humor has generally received a bad reputation in professional settings.4 Humor can increase group cohesion, bring individuals together, and alleviate tension. On the other hand, it can disparage others, create misunderstandings, or foster isolation and division and thus hinder the learning environment. So how is it that sometimes humor is amusing and other times it is offensive? … Address correspondence to Robert A. Dudas, MD, Department of Pediatrics, Johns Hopkins All Children’s Hospital, 601 5th Ave S, Room 5206, St Petersburg, FL 33701. E-mail: rdudas{at}jhmi.edu