BACKGROUND Community-based education (CBE) was developed thirty years ago in response to the maldistribution of physicians and subsequent inequity of health care services across geographical areas in developed and developing countries. Several medical schools in Nigeria report adopting CBE. This study seeks to identify and describe the CBE programs in accredited Nigerian medical schools and to report students' assessments of the knowledge and skills gained during their community-based educational experience. METHODS Researchers developed a questionnaire that was distributed to student representatives at 19 of the 20 accredited medical schools. Student representatives distributed the questionnaire to 20 final year medical students and returned the completed questionnaires to the researchers. Quantitative data were entered into SPSS 14. RESULTS Most students from CBE schools participated in CBE experiences of 4 to 8 weeks duration during their fifth or sixth year and paid for their food and transportation costs. Medical school personnel supervised the students who were also often assisted by community personnel. Students' rated highest their learning about environmental-related health risks and how to identify community health problems. They rated lowest what they learned about how to train health workers and how to implement and analyze results of community health interventions. CONCLUSIONS CBE teaches future physicians how to function as health care providers in underserved communities. CBE curricula in Nigeria are addressing most, but not all, of the validated CBE generic objectives. Most notably, the curricula are not providing adequate education in the implementation and analysis of results of a community health intervention.