A 51-year-old patient, who had experienced photosensitivity from childhood on, fell ill with an icterus accompanied by abdominal complaints. At the age of 46 years an erythropoietic protoprophyria had been diagnosed by an excessive protoporphyrinemia. Meanwhile, in consequence of the protoporphyria's erythrohepatic progression, a biliary liver cirrhosis developed, associated with portal hypertension and marked splenomegalie. As a remission of the protoporphyria-induced hepatobiliary complication could not be achieved by conservative medical treatment, the indication for orthotopic liver transplantation was established. The operation proceeded without complications, and the postoperative course, too, revealed no problems. With primarily good bile production, bilirubin and aminotransferases soon declined to normal values. Urinary coproporphyrin excretion was found to be normal after transplantation, only a domination of isomer I still peristed. Furthermore, a distinct elevation of protoprophyrin continued to exist both in erythrocytes and plasma as expression of the immanent enzyme deficiency typical for the genodermatosis protoporphyria. In the liver explant a micronodular transformation of parenchyma was found besides a deposition of reddish-brown protoporphyrin pigment in hepatocellular cytoplasma and Kupffer's cells, in addition to pigment casts in the canaliculi and within single portal bile ducts.(ABSTRACT TRUNCATED AT 250 WORDS)