Magnetic resonance imaging findings in 13 patients with acute transverse myelitis are reviewed. In 12 cases centrally located high intensity signal extending over few spinal segments was noted. The lesion occupied more than two thirds of the cord's cross-sectional area in 8 patients. Central dot sign was noted in 7 patients. Variable cord enlargement was seen in 5 patients. Contrast study in one patient showed peripheral enhancement. The MR characteristics that help in differentiating transverse myelitis from spinal form of multiple sclerosis are discussed.