An autopsy case of ataxic form of Creutzfeldt-Jakob disease (Brownell and Oppenheimer, 1965) was reported. The patient, a 71-year-old male, noticed ataxic gait at the beginning of June in 1988, and was admitted to the Hiroshima City Hospital for the neurological examination at the end of June. He showed ataxia of the left arm and legs and diplopia. Gradually he became delirious at night. On July 16, tremor-like involuntary movement of the left hand was noticed. On July 20, he became somnolent and doubly incontinent. Myoclonus and paratonic rigidity were also observed. The EEG showed periodic synchronous discharge on July 25. The brain CT and MRI were normal. He became apallic gradually and died on October 28. The duration of illness was 5 months. At autopsy, brain weighed 1000gr. Cerebral atrophy and slight enlargement of the ventricles were observed. The cerebellum was also slightly atrophic. Histologically, the destruction of the cerebral cortical layer, slight sieve-like spongy state of the neuropil, slight neuronal loss of the thalamus and sieve-like spongy state of the striatum were observed. The cerebellar lesion was the most severe, where granular cell loss and gliosis of the cortex were observed.