The object of this study is to describe the sequential change of high signal of the striatum on T2-weighted MRI in sporadic Creutzfeldt-Jakob disease (CJD). Three cases of autopsy-proven sporadic CJD and a total of 18 serial MR images are included in this study. The degree of high signal of the striatum on T2-weighted MRI was evaluated by two neuroradiologists and divided into four grades by mutual agreement. Initial MRI of all three cases showed a slightly high signal of the bilateral striatum, and the conspicuity of the high signal became more prominent as the disease progressed. In each case the pathological change of striatum and globus pallidus was compared with the high signal on the last MR image.