Abstarct: Objective: High-fat diets and sedentary life-style are associated with health problems such as obesity, hyperlipidemia, insulin resistance and non-alcoholic fatty liver disease (NAFLD). Studies have shown that high-fat diet increases the accumulation of triglycerides in hepatocytes. Accumulation of fat in hepatocytes can lead to liver damage, which can be identified by various invasive and non-invasive methods. Liver disease can be diagnosed by the circulating level of aminotransferase enzymes. Serum levels of these aminotransferases indicate the status of hepatocytes, the increase of which is associated with liver disorders and diseases. In contrast, exercise has been shown to reduce visceral fat level and improve lipid profile and insulin resistance, which may subsequently improve liver function. In this study, we investigated the effect of high-intensity interval training along with high-fat diet on serum triglyceride and aminotransferase levels in male Wistar rats. Methods: in an experimental, 40 male Wistar rats (age: 10-12 weeks, mean weight: 200 g) were housed in a quiet and controlled condition (temperature: 20±2 ° C, humidity: 50 ± 10%) under a 12h light/dark cycle. Animals were acclimatized to the lab condition for 1 week and then were familiarized with exercise procedure on electronic treadmill over 1 week. Then, the animals were randomly divided to four groups of control, high-fat diet, high-intensity interval training, and high-intensity interval training + high-fat diet. HIIT program consisted of 6-12 reps of 2 min high intensity exercise (85-90% of maximum speed) interspersed with 1 min low intensity exercise (45-50% peak speed). Exercise protocol was applied 5 sessions a week over 12 weeks. The high-fat diet group were fed with a high-fat diet and the other groups received a standard diet over 3 months. Forty-eight hours following last session animals were anesthetized by ketamine and xylazine (90 mg•kg-1 and 10 mg•kg-1, respectively) and blood samples were taken from left ventricle. Blood samples were used to measure serum levels of triglyceride, alanine aminotransferase and aspartate aminotransferase. Results: Data indicated the high-fat diet over 12 weeks significantly elevated serum levels of triglyceride, ALT and AST in male Wistar rats. In contrast, high-intensity interval training significantly reduced these parameters compared to the high-fat diet group. Conclusion: In spite of the effect of high-intensity interval training on serum aminotransferases increased by high-fat diet, the difference between high-intensity interval training + high-fat diet and control group indicates that high-intensity interval training could not return serum triglyceride and aminotransferase levels to baxseline levels. Therefore, the role of nutrition and dietary modifications in seem to be very prominent. High-intensity interval training alone has a modest effect on mextabolic control.