Type II diabetes is a common disorder whose prevalence is increasing in the United States and throughout the world. Type II diabetes is also associated with several other metabolic abnormalities such as central obesity, hypertension, and dyslipidemia, which contributes to the very high rate of cardiovascular morbidity and mortality. The main pathologic defects in diabetes consist of excessive hepatic glucose production, peripheral insulin resistance, and defective beta-cell secretory function. The duration and severity of the hyperglycemia dictate the microvascular complications, no matter what the etiology of the glucose intolerance, and the goals of therapy should be similar to those of insulin-dependent type I diabetic patients. Initiation of nonpharmacologic therapy should be started as soon as the diagnosis is made. Pharmacologic agents should be initiated if the glycemic goals are not met with a 3-month trial of diet and exercise. The cornerstone of therapy consists of a regular exercise routine along with a diet consisting of 40% to 50% complex carbohydrates, 10% to 20% protein, and monounsaturated fats such as canola oil and olive oil. If nonpharmacologic therapy does not achieve adequate glycemic control, initiation of an oral antidiabetic agent is warranted. In addition to the sulfonylureas, which work by stimulating insulin secretion, we now have metformin, which inhibits excessive hepatic glucose production; acarbose, which delays the absorption of carbohydrates in the gut; and troglitazone, which reduces insulin, resistance primarily in skeletal muscle. The selection of an initial oral antidiabetic agent depends on patient characteristics such as the presence of obesity and dyslipidemia, the duration of diabetes, and other concomitant conditions. Combination therapy with two or three of the different classes of oral antidiabetic agents is effective and has been used throughout the world. When maximum doses of oral antidiabetic agents do not adequately control glycemia, insulin therapy is necessary. In selected patients, combination therapy consisting of bedtime intermediate-acting insulin in addition to daytime oral antidiabetic agent(s) can be an effective method to normalize glucose control without the need for rigorous insulin regimens. When combination therapy fails, a split-mixed regimen using premixed 70/30 insulin prebreakfast and predinner can be very effective in obese subjects. In thin insulin-requiring subjects with type II diabetes, more intensive regimens may be required. In general, the risk of severe hypoglycemia is quite low in patients with type II diabetes, and the main adverse effect of insulin therapy is weight gain. Prevention and aggressive treatment of glucose intolerance and the other adverse metabolic conditions associated with type II diabetes will not only have a positive effect on the quality of life but also provide long-term cost savings.