Complications in apheresis affect on the average 40% of treated patients and 10-14% of the procedures. The mortality rate is 1/500 treated patients. The utilization of more complex techniques, central catheters, plasma infusion and even more the superimposition of different factors increase the incidence and gravity of side effects. Very influent are also the underlying pathologies and the clinical conditions; particularly at risk are patients with TTP/HUS and GBS. However, PE represents a relatively safe therapy in which prevention of complications requires a particularly diligent personnel and a careful evaluation of indications.