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Background and Objective: Thyroid hormones have a key role in regulation of metabolism and function of the tissues. This study was carried out to evaluate the effect of alcoholic extract of Portulaca Oleracea on serum level of thyroid hormones in hypercholestrolemic rats. Methods: In this experimental study, 60 adult male Wistar rats were randomly allocated into six groups including: control group with normal diet, fat diet group with high fat diet and interventional groups were received high fat diet and alcoholic extract of Portulaca Oleracea with maximum dose (800 mg/kg/bw), moderate dose (400 mg/kg/bw), minimum dose (200 mg/kg/bw) intraperitoneally for 21 days and finally, animals in atorvastatin group were received high fat diet with atorvastatin (10 mg/kg/bw, intraperitoneally) for 21 days. After the end of this period, T3, T4, TSH and total cholesterol measured for each animal. Results:Serum level of T3 and T4 in the experimental groups which were received Portulaca Oleracea extract and atorvastatin group significantly increased in compared to controls (P<0.05). Serum level of TSH level significantly reduced in the experimental groups which were received Portulaca Oleracea extract and atorvastatin group in compared to controls (P<0.05). The serum total cholesterol level significantly reduced in the experimental groups which were received Portulaca Oleracea extract and atorvastatin group in compared to fat diet group (P<0.05). Conclusion: Portulaca Oleracea extract with increasing of secretion of thyroid hormone reduced the total cholesterol and TSH animals with hypercholesterolemia.