In 87 patients from a total of 90 a posttraumatic or postoperative diaphysal or epimetaphysal shaft-pseudarthrosis could be found. In 53 patients we used the plate-osteosynthesis (tension-, axial compression-, neutralisation-, bridge- and bilateral plates). In 24 patients this was combined with other procedures (decortication, resection of the fragments or the pseudarthrosis or surplus--callus, implantation of autogenous bone). Using plate-osteosynthesis in all cases of aseptic or defected pseudarthrosis we gained osseous stabilization and healing, with good function, as was shown by followup studies. In infected pseudarthroses (8 patients) several operations were necessery for complete healing. Successfull treatment of aseptic and infected pseudarthrosis is based on the correct indication as well as correct choice and application of the plate.