STUDY DESIGN: Retrospective study on 12 cases of intradural extramedullary tumor. OBJECTIES : To analyze the clinical symptoms and the outcome of the treatments in the 12 patients who had intradural extramedullary tumors. SUMMARY OF LITERATURE REVIEW : In order to provide a good prognosis and achieve a satisfactory clinical outcome for the treatment of intradural extramedullary tumors, early diagnosis and careful surgical resection is necessary. MATERIALS AND METHODS: Twelve cases of intradural extradmedullary tumors were treated surgically from September 1990 to July 2000. Of the 12 cases, 7 were male and 5 were femal. Average follow-up period was 37 months. Mean age of the cases was 48.3 years. The followings were analyzed; 1)histopathologic diagnoses, 2)locations of tumors, 3)clinical findings, 4)duration of symptoms, and 5)radiologic findings. In addition, both changes of symptoms as well as neurologic findings during the preoperative stage and the postoperative follow-up were evaluated according to the Frankel's and Kim 's criteria. RESULTS: Histiopathologic results were as follows; 6 cases (50%) confirmed as schwannoma, 3 cases (25%) as meningioma, 1 case as epidermoid cyst, 1 case as neurofibroma, and 1 case as arachnoid cyst. Locations of tumors were as follows; 6 cases (50%) located in the thoracic region, 4 cases (33%) located in the lumbar, 1 case located in the cervical region, and 1 case located in the sacrum. Clinical findings were as follows: 6 cases complained of back pain and radiating pain to leg, 6 cases noticed motor weaknesses and sensory changes of varying degrees. The average duration from initial symptoms to admission was 57 months (23-140 months). Laminectomy and complete resection of tumors were performed in all cases. Posterior spinal fusion with instrumentation was necessary only in one case. The preoperative Frankel's grades were as follows; 6 cases were in grade C, 4 cases in grade D, and 2 cases in grade E. At the final follow-up, all cases were graded as E . CONCLUSION: The Early diagnosis and careful surgical resection for intradural extramedullary tumors provide for a good prognosis as well as a positive clinical outcome. Intradural tumors should be included in the differential diagnosis of spine diseases and considered as a subdivision of orthopaedic spine surgery.