Diabetes mellitus affects approximately 17 million adults in the United States and has profound implications in terms of long-term microvascular and macrovascular complications and their associated costs. In type 2 diabetes, insulin resistance and a relative beta-cell defect are the underlying pathologic problems leading to hyperglycemia. Notably, insulin resistance is also associated with obesity, dyslipidemia, and hypertension. Diabetes can be defined as a disease of accelerated cardiovascular deterioration associated with elevated blood glucose levels. Glycemic control has been shown to reduce the long-term complications associated with diabetes. Although medical nutrition therapy and appropriately prescribed increased physical activity are important components of a diabetes management plan, most patients need medication to lower glucose to near-normal levels. Therapeutic options for treating hyperglycemia include sulfonylureas and other insulin secretagogues, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, and insulin. An antidiabetic agent that improves insulin sensitivity is an excellent choice for early treatment of type 2 diabetes because it may delay or prevent complications associated with this disease. Because of the progressive nature of type 2 diabetes, aggressive intervention early in the course of the disease, including combination therapy, is often necessary.