The treatment of non-insulin-dependent diabetes mellitus (NIDDM) is based on dietary and oral hypoglycemic therapy. Present therapy includes diet and exercise, sulfonylureas, biguanides, and, if these measures fail, incremental doses of insulin. Current therapeutic strategies include the combination of different agents in an attempt to optimize glycemic control. Acarbose, an alpha-glucosidase inhibitor which delays carbohydrate digestion and the subsequent absorption of glucose, has been used with other agents to improve glycemic control. Also, in several clinical trials, acarbose monotherapy has been shown to result in significant reductions in postprandial plasma glucose levels as well as glycosylated hemoglobin. This agent is a useful addition to the current armamentarium for the treatment of NIDDM. Recently, the usefulness of acarbose as a first-line drug for the treatment of NIDDM has been evaluated and is reviewed here.