Background: There is some evidence that humor can be used effectively in teaching, to maintain student interest in the material and potentially to reduce academic stress. Purpose: To examine the relationship between students' appreciation of a professor's use of humor and course evaluations. Methods: 128 undergraduate and graduate students completed course evaluations following enrollment in epidemiology and public health classes. Course evaluations included a single "custom question" that assessed perceived funniness of a joke. Primary outcomes were student ratings of the perceived funniness of a joke, student ratings of a professor's effectiveness, and student evaluations of the course overall. Results: Perceived funniness of a joke was positively and significantly associated with evaluations of the instructor and course overall. Discussion: The study supports the use of humor as a pedagogical technique, so long as the jokes are actually funny. Translation to Health Education Practice: Humor can be used as a teaching tool, especially to increase student attention and perhaps to reduce stress.