There are no reports on effects of large blood losses in acute hepatic porphyria. In the present study we report the experiences of repeated large therapeutic phlebotomies in a patient with porphyria cutanea tarda coexisting with variegate porphyria. Neither a series of 12 phlebotomies, 300 mL each, resulting in a 17% decrease in blood haemoglobin, nor a single 400 mL phlebotomy activated the acute porphyric condition. It is concluded that the increased bone marrow metabolic throughput resulting from blood loss, in acute types of porphyria does not overload the normoblast or leukocyte precursor haem synthetic pathways in a way which will increase porphyrin precursor excretion or trigger acute porphyric symptoms.