Purpose: Tibolone is a sinthetic estrogen used to minimize menopause symptoms. It is usually welltolerated, and liver toxicity has been previously reported only on one occasion. A 45-year-old female with an uneventful medical history was taking tibolone 2.5mg/day for six months. She developed acute hepatitis with hepatocellular pattern (R=12). On routine blood work, the patient was found to have abnormal liver tests (ALT 600 UI/L, AST 280 UI/L, GGT 400 UI/L e FA 101 UI/L). Bilirubin was normal. At the evaluation in the hepatology clinic, the patient was asymptomatic, and physical examination was unremarkable. She had no history of alcohol intake, and denied over-the-counter use of other drugs or herb products. Tibolone therapy was discontinued, and complementary study was performed. We excluded viral hepatitis A, B, C, and E. The tests for metabolic liver disease and auto-immunity came back negative. Abdominal ultrasound showed no abnormal findings. Liver biopsy was performed, and revealed unspecific reactive hepatitis, compatible with drug-induced injury. After tibolone discontinuation, liver tests went back to normal in less than one month. CIOMS/RUCAM summed a total of nine points, assessing the relationship with the drug as highly probable. The fact that this patient had no previous history of liver disease, the negative complementary study, and the rapid normalization of liver tests after drug discontinuation, together with the supporting histological proof of toxicity, support the diagnosis of drug-induced liver injury.