The purpose of this study was to evaluate the renoprotective effect of the Garcinia mangostana L. pericarp extract (GMPE) on plasma creatinine and renal proximal tubules of streptozotocin-induced diabetic mice. This study used 36 male Balb/c strain mice. The samples were divided into 6 groups, namely KN (normal control), KD (diabetic control), KM (metformin control), and P (treatment group) comprising: P1 (50 mg GMPE/kg body weight), P2 (100 mg GMPE/kg body weight), as well as P3 (200 mg GMPE/kg body weight). The GMPE and metformin suspension were administered orally for 14 days on the diabetic mice. The diabetes was induced by intraperitoneal injection of STZ multiple at low-dose of 30 mg/kg body weight daily for five consecutive days. On day 15, mice were terminated. Data of plasma creatinine and renal proximal tubule damage levels or the number of swelling and necrosis cells were analyzed. Interestingly and it showed that administration of GMPE could reduce the plasma creatinine level and the ameliorate renal proximal tubules of streptozotocin-induced diabetic mice. In conclusion, the renoprotective effect of GMPE in streptozotocin-induced diabetic mice was associated with the attenuation in oxidative stress and inflammatory, which also had antidiabetic and antioxidant activities.