Methimazole is commonly prescribed for patients who are thyrotoxic. Cholestatic hepatitis is a rare but serious adverse event which may be associated with interventional therapy. In this case report, we present two Chinese women with cholestatic jaundice due to methimazole treatment. Both patients had a history of hyperthyroidism; initial laboratory studies of liver function were normal and cholestatic hepatitis occurred after treatment with methimazole. Concomitant liver disease, such as viral hepatitis (A, B, C, D, E), autoimmune hepatitis, primary biliary cirrhosis and calculus of bile duct, were excluded. Liver enzyme levels in both patients returned to normal after stopping methimazole therapy and taking hepatoprotective drugs. It is essential that patients are informed about the earliest symptoms of serious adverse effects of antithyroid drugs, such as hepatic toxicity, and that they are advised to stop taking the drug immediately and contact their physician if such symptoms occur.