The effect of different concentrations (2.5 and 5%) as powder and (250 and 500mg/kg/BW) as extract of chestnut fruits (Castanea sativa, M.) on obese rats were evaluated. Thirty six male albino rats weighting 140 ±10 g were used in this study and divided into 6 groups, 6 rats per each. Rats were fed on high fat diet (20% animal fat) to induce obese. Results showed that the highest body weight gain, feed intake and feed efficiency ratio recorded for 250mg/kgchestnut fruits extract, while the lowest recorded for 2.5 % chestnut fruits as powder with significant difference.The lowest ALT, AST and ALP liver enzyme of treated grouprecorded for group fed on 500mg/kgchestnut fruits extract with significant difference (P≤0.05).The highest cholesterol and triglycerides levels recorded for group fed on 2.5 % chestnut fruit powder while, the lowest value recorded for group fed on 500 mg/kg chestnut fruit extract with significant difference(P≤0.05).The highest (HDL-c) levels recorded for group fed on 500 mg/kg chestnut fruit extract.The lowest LDL-c and VLDL-c values recorded for group fed on 500 mg/kg chestnut fruit extract with significant difference(P≤0.05). While, the lowest uric acid, urea and creatinine values recorded for group fed on 500 mg/kg chestnut fruit extract with significant difference. As conclusion, obese rats treated with 500 mg/kg chestnut fruit extract had improvement lipid profile, liver and kidney functions compared withchestnut fruit powder.