Although most commonly used drugs such as biguanides, sulfonylureas, and more recently, thiazolidinediones, are effective in controlling fasting hyperglycemia, a high percentage of patients have sustained elevated hemoglobin A(1c) because of persistent elevation of postprandial plasma glucose (PPPG). alpha-Glucosidase inhibitors (AGIs) specifically target PPPG. AGIs have been shown in several randomized controlled trials to be effective in controlling blood glucose, whether they are used as monotherapy or in combination with other antidiabetic medications. Among the AGIs, acarbose has also been shown to decrease the risk of progressing to diabetes in subjects with impaired glucose tolerance (IGT). Studies have also suggested that acarbose could decrease the risk of cardiovascular disease, both in IGT and in diabetes. Furthermore, AGIs are very safe and are nontoxic drugs. Their only side effects are gastrointestinal, such as flatulence and diarrhea; however, these can be minimized by the "start low, go slow" approach. AGIs should be considered whenever postprandial hyperglycemia is the dominant metabolic abnormality.