Metronidazol, a commonly used antibiotic drug, has been very rarely associated with hepatotoxicity. In particular, no reports have appeared in the literature about cases of metronidazol-associated severe hepatotoxicity, leading to liver transplantation or death. We report on a case of acute fulminant liver failure in a young woman, who had, two years previously, developed jaundice after intake of metronidazol. During the current hospitalization, metronidazol treatment had been undertaken two weeks previously and also this time the patient developed severe hepatocellular injury and cholestasis. A viral etiology was ruled out as well as vascular, metabolic and malignant etiology. Although, the cause of the liver injury in this case is not proven, the relationship between this drug and two occasions of severe liver damage, suggests a positive challenge as well as rechallenge. An International algorithm was used for the assessment of the causality of a drug in this case of acute liver injury and a "probable" classification was obtained.