Chromium (Cr) plays an important role in body composition. Several human and animal studies of Cr supplementation have reported increases in lean body mass, often with concurrent decreases in body fat. The purpose of the current study was to determine the effects of supplemental Cr as chromium methionine (CrMet) on obesity index, body fat and serum lipids in rats. Thirty-six male Sprague-Dawley rats were divided into four groups of nine rats. Rats received a AIN-76 semipetrified basal diet or high fat diet supplemented with 300 ppb CrCl$_3$and CrMet as well as no added dietary Cr (referred to as Control, HF, HFCr, and HFCrMet). After 6 weeks on the respective diets, animals were killed and analyzed for differences in serum lipid concentrations. Rats supplemented with CrMet had a slightly higher naso-anal length and final body weight was decreased. The lowest obesity index and body fat content were found in CrMet supplemented animals (p〈0,05). Supplemental CrMet decreased the total lipid, triglyceride and total cholesterol. The significant differences observed were total cholesterol concentration for CrMet supplementation. These indicate that supplemental Cr, as chromium methionine, resulted in a significant decrease of obesity index and body fat and influence serum lipid concentrations, possibly by decreasing the body fat.