The Undergraduate Teaching Project was founded as a committee of the American Gastroenterological Association to improve medical school teaching of the pathophysiological basis of gastrointestinal and liver diseases. Twenty-six units of colored illustrations have been produced in 18 years, which are designed to be used by instructors to supplement their own material. The slides are the result of extensive reviews and revisions, a process that has created a unique repository of educational concepts utilized by most US medical schools and over 50 foreign schools. This brief summary of the genesis and operation of this venture may be of interest to other professional societies concerned with the development of teaching materials.