The clinical course of 12 patients with mushroom poisoning was evaluated in order to define the parameters considered to be relevant to the indication for liver transplantation. Eight patients recovered under conservative therapy; one patient died due to pre-existing, concomitant cardiopulmonary disease. In three patients transplantations had to be performed because of severe liver failure. On admission, the transplanted patients had a decreased Quick's test score and factor V value (< 10%). The peak of liver enzymes, serum bilirubin, serum creatinine, partial thromboplastin time and azotemia were not of any prognostic value. Main indications for liver transplantation were a very low initial Quick's test score and factor V value (both < 10%) and their inadequate response under substitution therapy. The development of encephalopathy and renal failure were further parameters indicating poor prognosis.