Symptomatic hepatic damage was diagnosed in six patients, three males and three females, during treatment with simvastatin. All patients recovered after discontinuation of the drug. One patient used the drug again, which led to another increase of serum liver enzyme activity. The period between the start of the treatment with simvastatin and the first symptoms of hepatic damage varied between 1 month and 3 years. If serum liver enzyme activities increase in patients using simvastatin, a causative relation should be considered.