Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative human prion disease. Based on its cause, CJD can be classified as sporadic, iatrogenic, familial, or variable. Most CJD cases (85%) are sporadic, while 10%-15% of cases are familial, and a minority are iatrogenic. The onset of sporadic CJD (sCJD) usually occurs in the seventh decade of life, with a median time to death of 5 months and with 80% of patients dying within 1 year. 1,2) sCJD is currently incurable. However, an accurate diagnosis in the early stage is crucial to predict the patient's prognosis and rule out the diagnosis of other treatable diseases. Here, we report about a patient who was misdiagnosed with recurrent stroke based on brain diffusion-weighted magnetic resonance imaging (DWI) findings, which corresponded to hemiplegia, and who had an unusual clinical course that showed stepwise deterioration.