We report an autopsy case of multiple system atrophy (MSA) presenting with rapid progression of autonomic disturbance. He was admitted to our hospital because of gait disturbance and dysarthria. The patient was a Japanese man, who first noticed gait disturbance and dysarthria at age 58, followed by syncope 3 months later. He developed urinary incontinence and frequency of urination 8 months after the disease onset. His gait disturbance, dysarthria, syncope, and urinary symptoms progressed, and he was admitted to the department of neurology 1 year after the onset of the disease. He was clinically diagnosed as having MSA and was followed in the outpatient office. He deteriorated rapidly and was readmitted to the department of neurology 19 months after the onset of the disease. Physical examination showed orthostatic hypotension. Neurological examination revealed nystagmus, dysarthria of cerebellar type, increased deep tendon reflexes, bilateral positive Babinski signs, ataxic and spastic gait, mild right hypesthesia and hypalgesia, impotence, constipation, and urinary incontinence. Routine blood examination showed slight anemia, elevated BUN, GOT, and blood sugar. Electrocardiography revealed sinus tachycardia and chest rentogenogram showed cardiac enlargement. Brain MRI showed atrophy of cerebellum and pons, and lacunae in basal ganglia. Autonomic function tests revealed abnormal in head-up tilt test, and CVR-R in May and November 1995. However 123I-MIBG myocardial scintigraphy showed normal uptake of MIBG in May 1995 and decreased uptake in November 1995. He deteriorated rapidly and died in May 1996. Autopsy findings revealed not only prominent olivopontocerebellar and slight striatonigral lesions, but also autonomic lesions with massive appearance of glial cytoplasmic inclusions. He was pathologically verified as having MSA. In the present patient, autonomic nervous system, especially cardiac sympathetic nerve, deteriorated rapidly, which might result in short duration of the illness.