The fourth edition will give a new, complete overview of the therapeutic apheresis (TA) with all semi- and selective methods, which are available. All methods, their functions, indications, clinical results, criticisms, and future aspects are discussed. This edition contains 580 pages including 117 tables, 85 figures, and 3380 references. In 6 chapters historical highlights, methods of unselective, semi-selective and selective separation procedures, complications, side effects of TA, and clinical results of different diseases are mentioned. Possible indications of TA are shown in pediatric diseases. Semi-selective and selective separation methods such as cascade-filtration, cryofiltration, plasmaperfusion, fibrinogen-adsorption, different methods of Immunoadsorption, LDL-apheresis, LDL hemoperfusion, and other methods, such as BioLogic-DTPP-system, Molecular Adsorbent Recycling system (MARS), Prometheus system etc., are discussed. Therapeutic apheresis in organ transplantation is mentioned. TA in organ transplantation offers new horizonts for ABO incompatible organ transplantation. This is discussed for renal-, liver-, heart-, lung-, and hematopoietic progenitor cell transplantation. The application of TA in transplantation is a corner stone of several conditions in ABO incompatible transplantation and enables to develop new strategies, the best organ transplantation in patients even with a high degree of immunonization or performed antibodies thereby expanding the use of living donation. Different clinical application committees have made a gradation of diseases, which are accepted for TA. All these new tendencies have influenced the clinical routine of treatments. The advantages are the elimination of pathologic substances and the interruption of pathogenic reactions. The disadvantages are the unselective elimination of all proteins by the unselective methods, the possible complications and the high costs. The authors try to define with regard to the literature the indications of different methods of TA. Especially in the present time, in which the resources in the health systems decrease enormously, a strong definition of indications for TA is necessary to save the health of our patients and to reduce the costs in future. This fourth edition should be a teaching and working book for all physicians, nurses, scientists, and industries, who are interested in this field. The experiments of modern biotechnologies to try a better imitating of the organ functions will be more and more encouraging, and we understand the pathophysiology of different diseases better and this enable us a more effective therapy in patients with a bad prognosis. Very important are various adsorption methods for plasma or blood of various diseases. This edition will give answers to different questions in this area.