The authors present short-term results of a 360 degrees fusion together with the experience in their own modification of minimally invasive retroperitoneal approach to the lumbar spine. In the course of 1998 and 1999 they operated on the total number of 21 patients using this approach. The anterior approach was considered as part of the combined operation on the lumbar spine which was indicated for degenerative, traumatic, tumorous and iatrogenic instability of the lumbar spine. They evaluated blood loss, duration of the surgery, duration of image intensifier exposure, restoration of the peristalsis, satisfaction of the patient with the operation by means of Visual Analog Scale and in 12 patients who exceeded a twelvemonth of the follow-up also healing of the fusion on dynamic radiographs of the lumbar spine. The results are very optimistic. As compared to a classical approach they achieved low blood loss, short duration of the surgery, a quick restoration of peristalsis and a reduction of postoperative morbidity. An undoubted advantage of the presented technique is the economic thriftiness as concerns special endoscopic devices, retraction frames, microscope, special instruments or expansion devices. During the evaluation of the fusion no development of a nonunion or migration of grafts or cages was recorded. Also the satisfaction of patients after the operation was high and in the following period it even increased. Key words: lumbar spine fusion, retroperitoneal approach, minimally invasive surgery.