To evaluate the capabilitiy of MR imaging to localize intramedullary tumors of the spinal cord and to distinguish solid from cystic components, MR images of 12 patients with surgically-proven intramedulary spinal cord tumor were retrospectively reviewed and correlated with surgical findings. Histologic diagnosis consisted of 3 astrocytomas, 4 ependymomas, 2 gangliogliomas, and one case of lipoma, lymphoma, and glioblastoma multiforme each. MR scans were obtained on a 2.oT or a 0.5T with T1-and T2-weghted spin-echo pulse sequences in sagittal and axial planes. Contrast enhancement was performed with Gd-DTPA in 9 patients. All tumors expanded the spinal cord and showed an extent of imvolvement ranging from 2 to 5 vertebral heights, except for the gangliogiomas which involved the spinal cord more extensively. Contrast enhancement was seen in all 9 patients. Intratumoral cavities were observed in 1 out of 3 astrocytomas and 2 gangliogliomas. Peritumoral syringomyelia was seen in 2 out of 4 ependymonas and 2 gangliogliomas. In most cases, the MR findings correlated well with the surgical findings with respect to the extent, distinctness of the tumor margin, intratumoral cavity, and associated syringomyelia. It is concluded that MR imaging is a very useful diagnostic tool in the evaluation of intramedularry spinal cord tumors.