Millet grains are nutri-cereals which have a high nutrient content. Excessive intake of a high-fat diet (HFD) leads to abnormal lipid metabolism, which further gives rise to various chronic diseases such as obesity, type 2 diabetes, heart disease and maybe cancer. The present study was conducted to investigate the effects of feeding supplementing HFD with millet flour (MF) on some physiological functions in rats. Thirty-five male rats were divided into five equal groups; the normal group (G1) was fed on a normal diet and the positive group (G2) was fed on HFD, while the other three groups were treated by feeding on supplemented diet with MF at levels of 5, 10 and 15%, respectively. Supplemented HFD with the different levels of MF significantly increased activities of antioxidant enzymes and serum HDL-c levels, and decreased body weight gain, feed efficiency ratio, serum levels of total lipids, triglycerides, total cholesterol, LDL-c, blood glucose, insulin, leptin, urea, creatinine, uric acid and MDA as well as the activities of liver enzymes (ALP, AST and ALT) and atherogenic index in obese rats, compared to that of the untreated obese rats. Histopathological examinations of liver and aorta also proved that supplemented diet with MF decreased the heart and aorta tissue damage in all treated rats. Conclusion: the present study concluded that millet grains may be healthful for patients with obesity. In addition, it improves many physiological functions, lipid levels and activities of antioxidant enzymes.