Background: Metformin is one of the alternative drugs to treat Diabetic mellitus type 2 (T2DM). One of the chronic symptoms of T2DM is the dysfunctionality of some vital organs. Aim: This study evaluates the role of metformin treatment to improve the liver and kidney functions of T2DM rats. Material and Methods: Forty rats were divided into four groups (n=10) as follows: group 1 (Gp1) was orally administered with 200 µl of distilled water. Gp2 was administered with metformin (200 mg/Kg) daily for two months. Gp3 and 4 were fed on high fat diet for 5 weeks, then Gp3 was injected with streptozotocin (STZ) (40 mg/Kg) once intraperitoneal (i.p.). Gp4 was injected with STZ as in Gp3 then administered with metformin as in Gp2. All rats were sacrificed to analyze the hematological, biochemical, and histopathological changes. Results: Metformin administration decreased the total body weight of both naïve and T2DM rats. Furthermore, metformin improves hepato-renal dysfunctions induced in T2DM rats as evidenced by decreasing the levels of ALT, AST, urea, and creatinine. The level of malondialdehyde was decreased while superoxide dismutase, catalase, and reduced glutathione levels were increased in the group of T2DM rats that were administrated with metformin. Treatment of T2DM rats with metformin increased C-Peptide and decreased glycose levels. Furthermore, histopathological investigations showed an improvement in the liver and kidney tissues upon treatment of T2DM rats with metformin. Conclusion: The treatment of T2DM rats with metformin for long period improves hepato-renal dysfunctions.