Laboratory studies such as electroencephalography, cerebrospinal fluid examination and diffusion-weighted magnetic resonance imaging (DWI-MRI) are valuable in the diagnosis of Creutzfeldt-Jacob disease (CJD),. However, these laboratory studies may not show the characteristic findings in the very early stage of the disease. Here, we present a case of CJD who had atypical neurologic presentation initially and had only a focal parietal 2-(18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) hypometabolism as the sole imaging abnormality at the beginning. The patient progressed rapidly, and showed typical neurological findings for CJD. The brain MRI was performed two weeks after the FDG-PET study, finally demonstrated increased signal intensity in DWI in caudat nucleus, putamen, and cerebral cortex, especially on left parietal region. Imaging methods demonstrating functional alterations in the brain should be obtained in the early period in patients with normal MRI suspected having CJD. Repeating DWI could also be an effective diagnostic approach.