We reported MRI findings in a 49-year-old woman with clinically diagnosed Creutzfeldt-Jakob disease (CJD). She was admitted to our hospital because of confusion, which initially appeared 5 weeks prior and was rapidly worsened. Two weeks later, she developed myoclonic jerks in her extremities with periodic synchronous discharges on EEG. Six months later, she became mutic. Brain MRI at 3 weeks after the admission demonstrated high signal intensities in the bilateral caudate nuclei and putamina on T2 weighted images (T2WIs). Diffusion weighted images (DWIs) showed hyperintensities in the basal ganglia and in the parietal and occipital cortices. Five weeks later, the abnormal intensities in the basal ganglia were still observed on T2WIs but decreased on DWIs. Five months later, the increased signal intensities in the basal ganglia had disappeared both on T2WIs and DWIs, but new hyperintensities appeared in the insula and the temporal area on DWIs. We concluded that DWIs may be useful for the demonstrations of a lesion in the cerebral cortex and the spread of lesions.