24 ABSTRACT Creutzfeldt-Jakob disease (CJD) is a rare dementing disease and is thought to caused by a prion. It is characterized by rapidly progressive dementia, ataxia, myoclonus, akinetic mutism and eventual death. The detection of 14-3-3 protein in the cerebrospinal fluid (CSF) may support the diagnosis of the CJD. Periodic synchronized sharp wave complexes are usually seen in electroencephalogram (EEG) during middle or late stages of disease. Diffusion-weighted imaging (DWI) is the most sensitive magnetic rezonans sequence technique in the diagnosis of CJD. Brain biopsy or autopsy is required for a definitive diagnosis of CJD. We present 60-year-old man diagnosed as sporadic CJD with isolated cortical involvement. The patient had dementia and myoclonus. The 14-3-3 protein was positive in the CSF. Bilateral asymetric cerebral cortical abnormalities with high signal intensities were seen well on the DWI and to a lesser degree also seen on fluid-attenuated inversion recovery (FLAIR) images. No abnormal signal were seen in the basal ganglia and thalamus. Through this case report we want to emphasize the importance of DWI as a conjunct to the conventional MR sequences in cases in which the CJD is the prediagnosis in order to detect the disease in its earlier stages.