An autopsy case of a 65-year-old female with dentatorubropallidoluysian atrophy (DRPLA) is reported. Her mother had gait disturbance and died at the age of 63. Her mother's brother developed psychotic symptoms. A daughter of her older sister was observed to have involuntary movement when she admitted to a mental hospital due to post-delivery psychotic state. Her younger brother has developed gait disturbance from about 56-year-old. Her older son has suffered from schizophrenia for long years. Since 58-year-old, she developed cerebellar ataxic gait and three years later, choreic involuntary movement developed in her extremities and face and progressively became prominent. Since 63-year-old, abnormal behavior brought about by the visual hallucination was occasionally observed. At the age of 63, she admitted to a mental hospital because of persistent persecutive delusion for her husband and was clinically diagnosed as Huntington's chorea for her remarkable choreic movement and psychotic state with dementia. Hypertension was also noticed. At the age of 65, she died of acute pneumonia. The duration of her illness was about 6 years. Histopathological findings of the CNS: the brain weighed 1,014 g. Brainstem and spinal cord were noticed to be relatively small in size. The cerebral cortex was well preserved. The cerebral white matter was diffusely demyelinated in the central semiovale where arteriosclerotic change of the small vessels was remarkable. Significant pathological changes consisted of marked symmetrical atrophy of the following two systems, i. e., dentatofugal pallidoluysian systems.(ABSTRACT TRUNCATED AT 250 WORDS)