OBJECTIVE To identify patients with type 2 diabetes mellitus who were in poor glycemic control and therapeutic adjustments that might improve control. METHODS Using electronic pharmacy data, we assigned subjects to 1 of 4 therapeutic categories. We then identified patients within each category who did not meet the recommended standard of glycemic control (glycosylated hemoglobin [Hb A(1c)] <0. 08 [<8.0%]) and studied their therapetic regimens for possible improvements. METHODS The subjects were 5,061 members of a large group-model health maintenance organization who had type 2 diabetes and 12 months of 1997 health plan eligibility. Main outcome measures The dosage of antihyperglycemic agents (sulfonylureas, metformin, and insulin) in relation to glycemic control as measured by the Hb A(1c). RESULTS A significant number (n = 1,570 [31.0%]) of persons with type 2 diabetes might improve their glycemic control with simple adjustments to their pharmacologic therapy. CONCLUSIONS Busy clinicians with heavy workloads can improve their management of diabetes by identifying patients whose glycemic control could be improved through a change in medication or simple adjustment in dosage.