The authors propose a classification of community-based education (CBE) as it is implemented all over the world. To create this taxonomy, they used reports in the literature of 31 active programs in many locations. A CBE program is an instructional program carried out in a community context, outside the academic hospital. The authors distinguish between programs that are developed primarily to provide services to an underserved community; programs that have a research focus; and programs that have as their primary goal the (clinical) training of students. These three major types can be subdivided in six minor types, among them community development programs, health intervention programs, and simple community-exposure programs. The ultimate goal of creating the taxonomy is to contribute to the development of a theory of CBE and provide a more systematic way to study CBE. In addition, the proposed taxonomy clearly demonstrates the various ways in which medical schools, their staffs, and their students can become involved with the communities served. CBE is not a unitary concept but a set of attempts to contribute to the quality of life in a particular community and, at the same time, create conditions for students to acquire hands-on understanding of the nature of the problems to be faced in future professional practice, and to develop relevant skills. The taxonomy also enables those involved in the development of CBE programs in their medical schools to see alternative approaches, which will help them choose the approaches that fit their particular educational goals. Last, it demonstrates the intricacies involved in the implementation of CBE, in particular the complexity of building a learning environment that is productive for students and, at the same time, responsive to community needs.