We report on a patient with acute intermittent porphyria, who received 8 AB0 incompatible units of packed red blood cells in an emergency situation. She never showed any signs of severe intravascular haemolysis. The patient died after four weeks because of a multi-organ failure caused from the malpractice of the porphyria. The problems of bedside testing, mixing field reaction, fresh frozen plasma and molecular-genetic determination of bloodgroup were discussed.