Trema micrantha (Ulmaceae) ethanolic crude extract (ECE) was screened for its hypoglycemic activity (250, 500 and 1,000 mg/kg v.o.). The animals were divided in three groups for the evaluation of the hypoglycemic effect: normal rats, rats with alloxan-induced diabetes and hyperglycemic normal rats. The antihyperglycemic activity was compared to the treatment with glibenclamide, an oral hypoglycemic agent. Serum glucose was analyzed after the treatment of the animals. The acute treatment with Trema micrantha ECE (250 and 1,000 mg/kg) caused a significant decrease in the blood glucose levels in diabetic rats, but no effect was observed among the normal treated rats nor the hyperglycemic normal rats. Trema micrantha's leaves are a good candidate for alternative and/or complementary medicine in the management of diabetes mellitus, since they showed beneficial effects on blood glucose levels.