This study proposes an alternative treatment based on Nyambaka propolis which can reduce the oxidative stress and hyperglycaemia caused by streptozotocin. Standard protocols were used to perform phytochemical screening. In vitro experiment was assessed to quantify the total of phenolic and flavonoid contents. The antioxidant activity of the extract was evaluated by the DPPH (2, 2–diphenyl-1-picrylhydrazil) antiradical scavenging assay. Diabetes mellitus was induced using single intraperitoneal injection of streptozotocin (100mg/Kg). The phytochemical screening revealed the presence of compound such as: saponins, phenolics, flavonoids, terpenoids and steroids. The total of phenolic and flavonoid contents was respectively (893.1±0.5 mg GAE/100g of extract) and (37.5±0.2 mg QE/100g of extract). The hydromethanolic (95/5) of propolis extract inhibited DPPH free radicals at (78.48±0.06%) with an IC50 of (0.096 mg/ml). Concerning antidiabetic activity, the dose of 500mg/Kg of propolis extract had the highest percentage reduction in glucose levels that means (78.13%) compared to the dose of 250 mg/Kg (65%) and the dose of 20mg/Kg of gibenclamid (77.6%). The hydromethanolic extract of Nyambaka propolis can be recommended to reduce the oxidative stress and hyperglycaemia caused by streptozotocin.