Nowadays, therapeutic plasma exchange (PE) is the most common apheresis procedure. Plasma is separated from corpuscular blood constitutents and replaced with a substitution fluid. Thus, PE is a non‐specific treatment modality. Its therapeutic effect is based on the removal of circulating, pathogenic immune factors, including autoantibodies. To date, PE is well established for several immune mediated neurological disorders. Whilst the first experience was acquired in acute life‐threatening conditions, such as the treatment of Guillain–Barré syndrome or myasthenic crisis, therapeutic success was later achieved in other chronic autoimmune diseases; PE was applied successfully in chronic inflammatory demyelinating polyneuropathy, paraproteinaemic polyneuropathy, stiff‐person syndrome and might also be tried in autoimmune diseases of paraneoplastic origin. From a novel aspect, PE was also established as an escalation therapy for steroid unresponsive relapses of multiple sclerosis, and thus has gained even more widespread attention. Humoral disease mechanisms dominate even more in neuromyelitis optica, as a subtype of MS, and usually respond to PE. Adding to its increasing application in clinical practice, the procedure is usually well tolerated. Possible adverse reactions of PE arise from the large‐size vascular access site, the use of replacement fluids and the need for anticoagulation. (Clin. Exp. Neuroimmunol. doi: 10.1111/j.1759‐1961.2010.0010.x, 2010)