This study aims to determine the decrease in glucose levels, MDA levels, and histopathological appearance of the pancreatic organs of Wistar white rats after administration of the ethanol-water fraction of longjack root. This study used a completely randomized design with four treatment groups and six replications. The treatment consisted of normal control, negative control (Na-CMC 0.5% 5 ml/200 g body weight), positive control (glibenclamide 0.09 mg/200 g body weight), and treatment of the ethanol-water fraction of longjack root with a dose of 500 mg/kg body weight. The results showed that the ethanol-water fraction of longjack root at a dose of 500 mg/kg body weight had antidiabetic activity comparable to that of glibenclamide at a dose of 0.09/200 g body weight, namely blood glucose levels and MDA levels in white rats of 123.55 mg/dl and 2.83 nmol/ml. The results of histopathological analysis of the pancreas of white rats showed that administration of the ethanol-water fraction of longjack root could repair damage to the islets of Langerhans due to the administration of streptozotocin-nicotinamide.