The MR appearance of the corpus callosum was investigated in 80 normal volunteers. Normal variations in appearance were recorded with regard to age, gender, and handedness. The MR studies of 47 patients with a wide spectrum of callosal disease were also reviewed. Abnormalities included trauma, neoplasia, congenital abnormalities, vascular lesions, and demyelinating and inflammatory conditions. The information provided by MR was compared with that obtained from other radiographic examinations, particularly CT and angiography. In all cases MR provided as much, and frequently more, information than was obtained by other imaging techniques. We believe that MR should be the primary imaging technique for the evaluation of corpus callosal disease.