This study evaluated the effects of different forms of chromium supplements on serum glucose, insulin and lipid concentrations in rats. Sprague-Dawley male rats were randomly assigned to one of three dietary groups and fed AIN-76 semi-purified basal diets supplemented with 300 ppb Cr from Cr methionine (CrMet) and Cr chloride $(CrCI_3)$ or without Cr (control). By the end of the $4^{th}$ week, all rats were decapitated, blood collected, and serum glucose, insulin and lipid concentrations were determined. The CrMet and $CrCl_3$ supplementation did not affect weight gain and feed efficiency ratio. However, feed intake was significantly higher in CrMet groups than control (p < 0.05). CrMet-supplemented rats had markedly increased insulin levels (p < 0.05) compared with controls. Serum lipids were not significantly different between the control and the CrMet groups. $CrCl_3$ supplementation decreased total cholesterol and triglyceride, but the decreases were only significant for the control group. $CrCl_3$ supplementation was associated with significant decreases in total cholesterol compared with CrMet supplementation. These results indicate that CrMet supplementation is effective for increasing serum insulin, and $CrCl_32$ may improve lipid concentrations, because we observed decreased serum total cholesterol and an improved total cholesterol/HDL-cholesterol ratio (THR).