Plasma exchange (PE) is a technique of extracorporeal blood purification which removes large molecular weight substances from plasma. The Department of Dialysis, Zagreb University Hospital Center's database, which includes data on 509 patients, or 4857 PE treatments, was retrospectively analyzed to test the safety of PE. A total of 231 adverse reactions were recorded (4.75% of treatments). The most common complications were paresthesias (2.7%), hematoma at the puncture site (2.4%), clotting (1.7%), mild to moderate allergic reactions (urticaria; 1.6%) and bleeding (0.06%). True anaphylactoid reactions were recorded in five procedures. The incidence of severe, potentially life-threatening adverse reactions was 0.12%. The prophylactic use of calcium and potassium was responsible for a low incidence of electrolyte disturbances. There was no lethal outcome associated with PE. When carried out by experienced staff, PE is a relatively safe procedure. The use of fresh frozen plasma is associated with a higher rate of adverse reactions.