This study aims to develop a patient-based measure of the complications of type 2 diabetes that can be used in examining its relationship with health-related quality of life (HRQOL) and utilization of health services. Using questions analogous to those typically employed by clinicians, we developed a 17-item questionnaire to identify prior diagnoses and current symptoms of 6 common complications of type 2 diabetes. We administered it to 419 patients with type 2 diabetes who were part of the Veterans Health Study, a larger prospective investigation of veterans receiving ambulatory care. From the responses, we calculated a simple sum of the 6 complications. We examined the correlation of this Diabetes Complications Index (DCI) with use of diabetes-related medical resources, outpatient doctor visits, HRQOL, duration of diabetes, and the degree to which patients perceived their health to be diminished by diabetes. The DCI was significantly correlated with the degree to which patients perceived their health to be diminished by diabetes (r = 0.35, P = .0001), utilization of diabetes-related resources (model R = 0.15, P = .0001), outpatient doctor visits (model R = .08, P = .001), and duration of diabetes (r = 0.11, P = .04). It had a good correlation with aspects of HRQOL that reflect physical function when controlling for age and comorbid conditions (model R = 0.23, P = .0001). The DCI shows promise as an efficient method for assessing the effects of type 2 diabetes on HRQOL and predicting utilization of medical resources.