The potential to treat life-threatening conditions with therapeutic plasma exchange (TPE) is limited to a few situations. In severe pulmonary hemorrhage as a complication of several immune disorders (e.g., antiglomerular basement membrane antibody disease, Wegener's granulomatosus, lupus erythematosus), TPE should only be considered after conventional measures (mostly pulses of methylprednisolone) have been applied. Idiopathic familial and nonfamilial thrombotic thrombocytopenic purpura as well as the subset of the hemolytic uremic syndrome not associated with diarrhea are clear indications for TPE using fresh frozen plasma as replacement fluid. Patients with myasthenic crisis will also benefit from TPE and will improve within 1 day. Acute pancreatitis as a complication of the chylomicronemia syndrome has a poor prognosis and should be treated with TPE without any delay. In the case of drug overdose or intoxication, the efficiency of TPE to remove the offending drug is usually overestimated. In this situation, TPE is useful only when the plasma protein binding of the substance is high (>80%) and the volume of distribution is low (<0.2 L/kg body weight). TPE is not without risks and hazards (e.g., vascular access, bleeding, allergy), which should also be considered when discussing this extracorporeal therapy in otherwise refractory clinical conditions.