The aim of this prospective study was to investigate the incidence, clinical features and the short- and long-term clinical course of hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) in Japanese patients. Eighty-seven consecutive patients with liver cirrhosis presenting with complications of portal hypertension underwent TIPS. The mean follow-up period after TIPS was 866 days. During the follow-up, HE occurred in 52% of patients throughout the follow-up period. The cumulative incidence of post-TIPS HE was 50.5+/-5.6% at 1 year (mean+/-S.D.). Most cases (89%) occurring within 7 days were easily controlled by the conventional therapy. Only two patients developed severe chronic HE, which was treated by reducing the shunt diameter. Older age, indication for TIPS (ascites) and higher retention rate of indocyanine green at 15min were identified as risk factors for post-TIPS HE. During long-term follow-up, the incident of post-TIPS HE decreased among survivals. The cumulative survival rate was similar in patients with or without post-TIPS HE. Our results indicate that post-TIPS HE are a frequent complication, particularly in the early months after TIPS. However, it can be easily managed in the majority of patients. The development of post-TIPS HE is not associated with poor prognosis in TIPS patients.