BACKGROUND: The leaves of have been used traditionally for the management of diabetes mellitus. Thus, this study aimed to evaluate the Antioxidant and Antihyperglycemic Effects of leaves crude extract in streptozotocin-induced diabetic mice. METHODS: To Evaluate the Antihyperglycemic, and Antioxidant Effects of Dovyalis Abyssinica Leaves Extract in Streptozotocin-Induced Diabetic Mice. Male Swiss albino mice were induced into diabetes using 100 mg/kg of streptozotocin. Mice were allocated randomly into six groups, six mice per group. The body weight and FBG measurements were done on days 0, 7th, 14th and 21st of treatment. Additionally, in vitro Antioxidant Activity of the Extract was determined using a DPPH assay. The data were entered into Epi-Data version 4.6, exported to SPSS version 26.0, and analysed by using a one-way ANOVA followed by a Tukey post hoc test, and P < 0.05 was considered statistically significant. RESULTS: Dovyalis Abyssinica leaves crude extract showed significant (P < 0.05-P< 0.001) blood-glucose-lowering activity. Moreover, the crude extract of reduced the fasting blood glucose level by 45.13 %, 52.51 %, 54.85 %, and 56.38 %, respectively, for DA 100, DA 200, DA 400, and GLC 5 mg/kg on the 21st day of treatment. After diabetic mice were treated with Dovyalis Abyssinica (100, 200, and 400 mg/kg) for 21 days, there was a significant increase in body weight as compared to diabetic control. Antioxidant activities of the leaf extract was found to be comparable to ascorbic acid with an IC50 of 140.04 μg/ml. CONCLUSION: The present findings revealed that leaves could be useful for the management of diabetes mellitus and other abnormalities related to this metabolic disorder. Thus, the present study may support the traditional use of for diabetes mellitus treatment.