Ratings by self, supervisors and peers of surgical residents were compared and contrasted, and the correlation between these ratings and the scores on the American Board of Surgery In-Training Examination (ABSITE) were studied. In addition, comparisons were made between ratings by residents of their peers (n = 32) and of attending surgeons (n = 61) with whom they had worked. The ratings consisted of scores from 1 to 5 in each of ten areas of clinical competence. Results indicated that over-all ratings by peers and supervisors were highly intercorrelated (r = 0.92; p less than 0.001) and that the average of over-all ratings by peers and supervisors correlated moderately with the total raw score on ABSITE (r = 0.58; p less than 0.01). Factor analyses suggested that the dimensions underlying the three sets of ratings differed considerably. It appeared that ratings by supervisors were influenced primarily by the interpersonal skills of the residents and secondarily by ability. In contrast, self-ratings by the residents were apparently mainly influenced by their perceptions of their own ability, followed by interpersonal skills and effort. Ratings by peers, on the other hand, seemed to reflect the over-all impression of the peers of the resident being rated. Comparisons between ratings of peers and attending surgeons by residents revealed that residents view attending surgeons as having a more balanced level of competence, across areas of both ability and interpersonal skills. Ratings of peers were lower than were the ratings of attending physicians by the residents in the areas of technical ability, knowledge of basic science and clinical knowledge.(ABSTRACT TRUNCATED AT 250 WORDS)