Objective: To assess the prevalence of, and quality of care for, diabetes mellitus among the understudied, yet growing, population of older, urban American Indians and Alaska Natives (AI/ANs). Design: Medical record review. Setting: Urban Indian primary care clinic in Seattle, Washington. Patients: All (N=550) AI/AN patients greater than or equal to50 years of age. Main Outcomes Measures: Provider-documented medical diagnoses and indicators of quality of care of diabetes. Results: Diabetes mellitus was documented in 113 (21%) of the medical records. Persons with diabetes were more likely than those without (P greater than or equal to .05) to be obese, and to have hypertension, coronary artery disease, and depression. Most patients with diabetes were treated with either insulin (43%) or oral hypoglycemic medication (39%), but 16% received neither. Screening rates within 12 months were high for glycosylated hemoglobin (72%), lipid profile (84%), and foot examination (72%), but were low for urinalysis (23%), ophthalmology referral (23%), and influenza vaccination (46%). Only 46% of patients had ever received pneumococcal vaccination, and even fewer (26%) had received tuberculin skin testing (24%). Although 65% of patients had ever been referred to a dietitian, only 40% had received exercise counseling. The total number of health problems was the factor most often associated with quality of care indicators. Conclusions: The prevalence rate of diabetes among this urban clinic population of older Al/ANs was high. Although performance of quality indicators was suboptimal, it was comparable to, or better than, that found in other older populations for many measures.