The study reported here revealed a very high incidence of unrecognized feelings toward the patient ("countertransference") and potentially harmful associated behaviors in a group of medical students at the midpoint of their training. Fifteen students were studied individually by the author during a clinical interview each student conducted with a patient. Typically, unrecognized feelings were fear of harming the patient, fear of loss of control, performance anxiety, and fears unique to the individual student (such as fear of cancer in self). One or more of these feelings were present in 14 of the students. Interview behaviors that were potentially deleterious were present in 13 students; avoidance and/or overcontrol of the psychosocial aspects of the interview accounted for 11 of these instances, while two students exhibited behaviors unique to the student. Although these students all had demonstrated adequate interviewing skills previously, the unrecognized feelings were, in each of the 13 instances, related to impaired interview performance. These data suggest the need for interviewing instructors to teach medical students about the concept of counter-transference in addition to interviewing techniques.