An 80% dysfunction rate at 2 years limits the use of transjugular intrahepatic portosystemic shunts (TIPS) in the treatment of complications of portal hypertension. The use of covered stents could improve shunt patency; however, long-term effect and safety remain unknown. Eighty patients randomized to be treated by TIPS either with a covered stent (Group 1) or an uncovered prosthesis (Group 2) were followed-up for 2 years. Doppler US was performed every 3 months. Angiography and portosystemic pressure gradient measurement were performed every 6 months or whenever dysfunction was suspected. Actuarial rates of primary patency in Groups 1 and 2 were 76% and 36% respectively (P=0.001). Clinical relapse occurred in four patients (10%) in Group 1 and 12 (29%) in Group 2 (P<0.05). Actuarial rates of being free of encephalopathy were 67% in Group 1 and 51% in Group 2 (P<0.05). Probability of survival was 58% and 45% at 2 years, respectively, in Groups 1 and 2 (NS). The mean Child–Pugh score improved only in Group 1 (from 8.1±1.6 to 7±2.2 at 2 years –P<0.05). We also compared the Doppler-US parameters between patent and dysfunctioning shunts. In patent shunts, the mean velocity within the portal vein was significantly higher but the performance of Doppler-US was not accurate enough to predict shunt dysfunction. In conclusion, the improvement in TIPS patency by using covered prostheses is maintained over time with a decreased risk of encephalopathy, while the risk of death was not increased.