The author gives account of a direct osteosynthesis--joining the defect of the interarticular part--made in case of spondylolisthesis in his department. They carry out the operation having modified the method of Buck as they use A-O malleolar compression screw instead of all threaded screw. Applying compression screws the author can ensure a successful osteosynthesis in case of a greater vertebral displacement. This method widens the indication area of the operation. The adventage of the operation over other ones made in spondylolisthesis is the fact that after the wound-healing the patient can get up and the lumbar spine will not be limited in motion. The operation was made in 16 cases until now and operative complication was not observed. They propose to make this operation as early as possible in case of definite spondylolisthesis to prevent the development of further progression.