The clinical and immunoserological data in 66 bone grafted patients are analysed. The importance of the immunological histocompatibility in bone allotransplantation is discussed in a short introduction. The method of transplantation is given and the clinical material is analysed in 3 tables. It is clear from the discussion, that in 6 out 66 patients there are data for an isoimmunization in result of the transplantation. Cytotoxins in the patients' sera are demonstrated after transplantation of frozen grafts. No HL-A antibodies are demonstrated following transplantation of bone grafts, treated after the method of Maatz and Bauermeister. The humoral antibodies are of a greater importance in transplantation of larger bone grafts, as well as of bone-joints complexes. It is acceptable that the immune conflict is of importance as regards to the pathological resorption of the graft. Often, the histocompatibility is a basical reason for the suppuration and sequestration of the graft. The antigenicity of the graft possesses an inductive action concerning the new bone formation. The importance of the osteogenic possibility of the bone-bed-recipient is underlined. It is desirable for a modern tissue bank to be able to offer bone grafts with determined specificity concerning ABO, Rhesus-D and HL-A systems. This will be a new perspective in the bone allotransplantation.