Diabetes mellitus is the most common disease in the world. One therapeutic approach for treating diabetes is inhibition of alpha-amylase and alpha-glucosidase activities to reduce postprandial blood glucose levels. In vitro tests showed that several plant extracts from Brazilian cerrado species can inhibit the activity of alpha-amylase and alpha-glucosidase. The extracts of Eugenia dysenterica, Stryphnodendron adstringens, Pouteria caimito, Pouteria ramiflora, and Pouteria torta showed strong alpha-amylase and alpha-glucosidase inhibitory activity. Eugenia dysenterica, P. caimito, P. ramiflora, and P. torta aqueous extracts exerted the highest activity against alpha-amylase (IC50 values of 14.93, 13.6, 7.08, and 5.67 mu g/mL, respectively) and alpha-glucosidase (IC50 values of 0.46, 2.58, 0.35, and 0.22 mu g/mL, respectively). Stryphnodendron adstringens ethanol extract also exhibited inhibitory activity against both enzymes (IC50 1.86 mu g/mL against alpha-amylase and 0.61 mu g/mL against alpha-glucosidase). The results suggest that the activity of these cerrado plants on alpha-amylase and alpha-glucosidase represents a potential tool for development of new strategies for treatment of diabetes.