Objectives : Onion (AlliumcepaL.) is one of the richest sources of flavonoids in human diet. In this study, we studied the effects of onion peel water extract (OPE) on the blood lipid profiles and glucose in rats. Methods : The experimental groups were divided with 5 groups (n = 6) of SD rats: normal diet + distilled water (NC), high-fat diet + Quercetin (PC), high-fat diet + onion peel water extract 4 mg/kg (OPE-4), high-fat diet + onion peel water extract 20 mg/kg (OPE-20), high-fat diet + onion peel water extract 100 mg/kg (OPE-100). Results : The liver fat showed significantly lower weights and size in the OPE-100 group as compared with NC group (p<0.05), The epididymal fat and retroperitoneal fat showed significantly lower weights and sizes in the OPE-4 and OPE-20 group as compared with NC group (p<0.05). The serum levels of total cholesterol, LDL cholesterol and triglyceride were significantly lower in the OPE-4 and OPE-20 group as compared with NC group (p<0.05). The OPE-4 and OPE-20 group showed higher HDL cholesterol concentration than NC group (p<0.05). Atherogenic index of OPE-4 and OPE-20 group was significantly lower in as compared with NC group (p<0.05). The serum levels of glucose significantly lower in the OPE-20 group as compared with NC group (p<0.05). Conclusions : In these results, we suggests that onion peel water extracts supplementation can reduces the serum lipid components and improves the lipid metabolism in hyperlipidemic SD rat induced with a high-fat diet.