A 75-year-old male visited Fuchu general hospital on foot because of possible acute mushroom poisoning. He had no symptom on admission. He twice ate some toxic mushrooms for lunch and for dinner on the previous day with his wife, who was found dead in her bed on the morning of his admission. A legally ordered autopsy was held on his wife, and a-amanitin was detected in her liver, brain and blood samples. Detection of a-amanitin in blood samples has never been reported in the literature. His liver and kidney failure rapidly progressed. He died on the 10th hospital day despite intensive treatment including hemodialysis and plasma exchange. On histological examination, his necropsy liver specimen revealed massive liver necrosis and new growth of pseudocholangioles, which apparently bore testimony to acute toxic mushroom poisoning.