OBJECTIVE. Our purpose was to estimate the incidence of encephalopathy after transjugular intrahepatic portosystemic shunting (TIPS) related primarily to the diversion of portal vein blood flow and to identify periprocedural factors to predict patients at risk. MATERIALS AND METHODS. All patients who underwent TIPS with at least 1 month of clinical observation after the procedure were monitored for clinically evident encephalopathy. Other variables that could individually induce encephalopathy were retrospectively analyzed for interrelationships with spontaneous or worsened encephalopathy. RESULTS. Of the 150 patients, 68 (45%) suffered from encephalopathy after TIPS, but in only 33 (22%) was it new or worse than baseline measurements obtained before TIPS; in 18 of these 33 patients, an underlying medical cause was implicated. Fifteen (10%) of the 150 patients developed mental dysfunction, usually mild and well controlled, thought to be related only to TIPS and not to any underlying morbidity. Low portal vein pressures after TIPS were found to be interrelated with new or worsened spontaneous encephalopathy (p - .04). Likewise, advanced age (>59 years old) weakly corresponded to the development of encephalopathy after TIPS. CONCLUSION. TIPS causes an acceptably low rate of encephalopathy that is usually mild. No specific variables exist for predicting the development or progression of encephalopathy after TIPS.