[en] To evaluate the specific radiologic findings of the dysgenesis of corpus callosum(CCD) on CT and/or MR images. The authors reviewed retrospectively CT and/or MR images of 10 patients with CCD. After classifying CCD into partial and total type according to the degree of its development, we investigated structural abnormalities on CT and/or MR images resulting from or related to CCD and then associated anomaly. The most common findings of CCD on axial planes of CT and/or MR images were dilatation of posterior part of the lateral ventricles(8/10) and feature of the bodies of the both lateral ventricles(8/10) in parallel. Sagittal and coronal planes of MR demonstrated exact extent of dysgenesis of the corpus callosum(5/5) and radiating pattern of gyri in medial surface of cerebral hemisphere extending the 3rd ventricle without interruption by cingulate sulcus(4/5). MR image of mid-sagittal plane appeared most useful in diagnosis of CCD because of its direct depiction of the whole length of corpus callosum. In most cases, however, CCD can be easily diagnosed with CT scan by characteristic findings of the dilatation of the posterior part of lateral ventricles and paralleling of the lateral ventricles