A 53 year old man with idiopathic portal hypertension (IPH) was admitted because of high fever and diarrhea. Nineteen years before admission, he had received splenic hilar renal shunt operation with proximal flush ligation of splenic vein due to gastric varices. Three months before admission, he had been admitted to our hospital for evaluation of liver dysfunction. Liver biopsy examination had revealed peri-portal fibrosis consistent with IPH. Aeromonas hydrophila was isolated from blood. Although he was treated with antibiotics plus dopamine, glucose-insulin therapy, and mechanical ventilation, he had severe septic shock, and died 29 days after admission. We have to take notice of A. hydrophila infection in cases of portosystemic shunt because they fall in severe septic shock.