PURPOSE: The purpose of this study was to evaluate the characteristic MR findings of intramedullary spinal cord tumors according to histologic diagnosis. MATERIALS AND METHODS: MR images of 34 patients with surgically-proven intramedullary spinal cord tumor were retrospectively reviewed. Histologic diagnosis revealed 15 ependymomas, ten astrocytomas, three hemangioblastomas, two oligidendrogliomas, one malignant schwannoma, one glioblastoma multiforme, one neuroblastoma and one ganglioglioma. MR images were analyzed for location, size, shape, signal intensity, and degree and pattern of contrast enhancement of the tumors. RESULTS: All tumors showed cord expansion and a varying extent of involvement ranging from 1.5 to 30cm. Variable degrees of contrast enhancement were seen in all cases. Cervical, cervico-thoracic, thoracic, and thoraco-lumbar spinal ependymomas accounted for three, two, six, and four cases, respectively, while four, two, and four cases of cervical, cervico-thoracic, and thoracic spinal astrocytomas respectively, were seen. Other tumors were located most commonly in the thoracic spinal cord. A sharply-defined tumor margin was seen in 13 of 15 ependymomas, in all three hemangioblastomas, one neuroblastoma and one ganglioglioma. Tumors usually showed slightly low- or iso-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Peritumoral cysts were seen in nine ependymomas, one hemangioblastoma, and one astrocytoma, while peritumoral hemorrhage was seen only in three ependymomas. Relatively homogeneous enhancement was seen in nine of 13 ependymomas, all hemangioblastomas and one neuroblastoma. All ten astrocytomas showed a poorly defined tumor margin and heterogeneous enhancement. CONCLUSION: On the basis of characteristic MR findings, intramedullary cord tumors may be histopathologically diagnosed.