The role of self-assessment of health was compared in 150 diabetic and nondiabetic male outpatients matched for age and race. Data were collected (1) directly from the patient at intake into the study and then again in 2 mo, (2) from the medical record, and (3) from the physician. Variables included background information, symptomatology, satisfaction with care, attitudes, use of medical facilities, medications, diagnoses, compliance and physician's estimate of patient's compliance, current health, and whether improvement was expected. A 2 x 2 factorial design was used to compare diabetic and nondiabetic patients with good and poor perceptions of health. Diabetic patients who viewed their health as poor had significantly more clinic visits, greater symptomatology, and were less satisfied with the doctor-patient relationship. The physician's rating of health did not confirm that this group actually had poorer health than the diabetic patients who perceived their health as good, and there was no difference in number of diagnoses between these groups. Data suggest that self-health perception is an important variable in diabetic patients. For those who see their health as poor, there may be a lack of concordance between patient and physician, which may result from these patients being more negativistic and difficult to treat. This may represent a group for whom a different type of treatment approach is needed.