Patients' cooperation with their medical regimen is of prime importance in the treatment of a chronic illness such as diabetes. A psychosocial model of behavioral prediction developed by Fishbein was used to examine compliance intentions among diabetic patients. Patients' beliefs about the consequences of following their diet were identified. Surprisingly, how important following the regimen was to "significant others" in a patient's life was a stronger predictor of behavioral intention than were the patient's own beliefs.