Kaempferia parviflora has been traditionally used in folk medicine. This study investigates the hypoglycemic effects of the methoxyflavone-enriched ethanol extract of K. parviflora (MKE) in streptozotocin-induced diabetic rats. Compared to the control and vehicle groups, MKE at 150 and 300 mg/kg significantly decreased blood glucose, comparably to glibenclamide. The damage to the Islets of Langerhans was found to be ameliorated in the MKE-treated groups, with twice the increase in the cell count of the Islets. Immunohistological staining showed the loss of insulin as characterized by diffuse staining of the cells in the pancreas of the streptozotocin-induced diabetic rats. MKE-treated groups showed an increase in insulin density in the pancreas of the diabetic rats, similar to the glibenclamide-treated group. MKE at both doses and glibenclamide decreased the hepatic MDA content, but statistical significance was found only for the glibenclamide-treated group. The degeneration of renal tubules and cell necrosis in the kidneys decreased in the MKE-treated groups.