This study identified characteristics of clinical teachers in ambulatory care settings that influenced ratings of overall teaching effectiveness and examined the impacts of selected variables of the clinic environment on teaching effectiveness ratings. A survey instrument derived from prior research and observations of ambulatory care teaching was sent to 165 senior medical students and 60 medicine residents at the University of Washington School of Medicine in 1988. A total of 122 (74%) of the seniors and 60 (71%) of the residents responded. Results indicate that the most important characteristics of the ambulatory care teachers were that they actively involved the learners, promoted learner autonomy, and demonstrated patient care skills. Environmental variables did not have a substantial influence on these ratings.