Spondylitis ankylopoetica cantinuin for years makes such demormaties that surgical interventions are needed for correction. In this stage no severe pain is felt but the movements of the colomna vertebralis are lost, the patients are bent forward looking down to the ground. From 1944 on many surgical technics have been used in our cases we prefered J. J. Herbert s technic. It is necessary to determine the sight of the osteotomy before the operation. The most suitable places for the osteotomy are in the cervical and lumbale portions of the colomna vertebralis. Although sometimes it may be needed to make an osteotomy anterioriy and posteriorly in our cases it has been possible to correct anterioriy by one operation. A plaster can t has been applied a week later laying the patient over the pillows in decubitus dorsalis position. The patients are permitted to get up after two months carrying a corsette tor six monts. No complications have been seen in nine of our cases all feeling theraselves quite well and happier after the operation.