After treatment with valproic acid a 19-year-old female patient with Friedreich's ataxia and generalised epilepsy died following acute hepatic failure with massive lactacidosis. The clinical symptoms were characterised by hyperventilation, increasing loss of consciousness and shock, leading to treatment-resistant hepatic coma. Morbid anatomy showed extensive confluent lytic necroses of liver acini with accentuation of centrolobular and intermediary structures as well as small and medium-sized fatty degeneration increasing from the periphery towards the centre. The disease picture is quite characteristic for being caused by valproic acid. As a safety measure liver function tests should be done should prodromal symptoms such as anorexia, weakness and apathy arise. If necessary the dosage has to be reduced or medication stopped. Serum valproic acid levels should remain in the lower half of the therapeutic range.