We report the cases of two adults suffering from acute hepatitis due to cyclofenil (Ondogyne), a drug proposed for the treatment of dysovulation and scleroderma. Hepatitis developed 30 and 102 days after the beginning of discontinuous administration of the drug. A challenge test was positive in both cases. The course of hepatitis was reversible after withdrawal of the drug. Hepatitis induced by cyclofenil is likely to be due to an hypersensitivity mechanism.