Ammodaucus leucotrichus aqueous extract has been shown an antihyperglycemic effect by inhibiting α-glucosidase, α-amylase and intestinal glucose absorption. This study aims to evaluate the pancreatic protective effect of Ammodaucus leucotrichus aqueous extract (AEAL) against experimental alloxan-induced diabetes in mice. Also, antioxidant activity, total phenolic and flavonoids content were evaluated. The preventive effect was performed on Swiss albino mice treated with the AEAL (150 and 300 mg/kg) before and after a single intraperitoneal alloxan injection. Percent surviving, fasting blood glucose, and body weight were measured. Furthermore, pancreatic tissues were collected for histopathological analysis to evaluate alloxaninduced tissue alterations. The antioxidant activity was determined by using three methods: measuring 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, oxidation of β-carotene/linoleic acid, and ferric reducing antioxidant potential assay. Total phenolic content was determined by Folin–Ciocalteu colorimetric method and total flavonoid content was measured by aluminum chloride colorimetric assay, and phytochemical screening was determined using standard qualitative methods. The administration of the AEAL at two doses of 150 and 300 mg/kg significantly attenuated alloxan-induced death and hyperglycemia in treated mice. Moreover, histopathological investigations revealed that the AEAL protected islets of Langerhans against alloxan-induced alterations. Moreover, AEAL revealed significant antioxidant activity and contains polyphenols, flavonoids, and betacyanins. The antidiabetogenic effect of A. leucotrichus could be due to their polyphenol and flavonoid components, which could react alone or in combination to scavenge the free radicals created by the alloxan.