The authors studied teaching of clinical skills and the supervision of clinical education of undergraduate medical students by reviewing students' patient-related experiences in required internal medicine clerkships in the United States and Canada during the 1979-1982 accreditation cycle of the Liaison Committee on Medical Education. The reported patient-related experiences of 180 medical students from 42 medical schools who took histories and performed physical examinations on 2,891 patients formed the basis of this paper. Variability in clerkship length, time worked, supervision, and patient mix suggests that additional quantitative data should be sought on medical students' experiences during the clerkship.