OBJECTIVE: The primary objective is to evaluate the clinical and economic outcomes of monotherapy with a sulfonylurea versus dual therapy with metformin and a sulfonylurea in a county health care system. METHODS: This is a retrospective, chart-review, study in which the patients will serve as their own controls, prior to starting dual therapy. All patients are evaluated two years prior to and post the addition of the second agent, metformin. Data collected will include the following: HbA1C, fasting blood glucose, lipid profile, and liver and renal function tests, adverse drug reactions, number of hospital and emergency room admissions, number and type of clinic visits, and number of operations/procedures/and diagnostic tests. The t-test for paired data is utilized to analyze the continuous variables. RESULTS: A total of 124 patients enrolled in this study, with a mean duration of diabetes of 6.68 years (SD 4.62). The average HbA1c on monotherapy is 10.5% versus 10.2% on dual therapy (NS). The average fasting blood glucose is 229mg/dL on monotherapy versus 192mg/dL on dual therapy (p<0.05). For the economic outcomes on monotherapy there is an average of 1.31 visits per patient versus 1.43 visits on dual therapy to the emergency room, hospital, and to ambulatory care clinics. On monotherapy, 31% of the patients had procedures and 37% had diagnostic tests, compared to 38% and 51% respectively, on dual therapy. CONCLUSIONS: This study does point to better clinical outcomes with dual therapy; however, there is a concurrent rise in the resource utilization. This increase could be due to more education on the physician side for preventive practices and to an increase in the patient access within the system. More research, especially prospectively designed studies, need to be conducted to determine the exact clinical and economic impact of dual oral therapy for diabetes.