A case regarding a newborn infant with severe Rh haemolytic disease, who presented with the bronze baby syndrome and eventually died, is reported. The postmortem examination showed marked extramedullary haematopoiesis in the liver and spleen, heavy hepatic haemosiderosis and mild intralobular cholestasis. The porphyrin content, which was assayed in different tissues, was very high in the liver, suggesting that the increased erythropoiesis seen in Rh haemolytic disease leads to an increased synthesis of porphyrins as by-products of haem synthesis. Phototherapy causes photodestruction, sensitized by bilirubin, of porphyrins (mainly copper porphyrins), yielding brown photoproducts.