We developed a new bioreactor for a bioartificial liver filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF) and in our previous study showed that this NWF bioreactor has promising in vitro efficiency. In the present study, we investigated the efficacy of the NWF bioreactor in a direct hemoperfusion experiment conducted to treat pigs with liver failure. Porcine hepatocytes were isolated from the whole liver of a Sangen strain pig. They were immobilized in a 200 ml column containing NWF via perfusion in a closed circuit for 24 h to prepare a NWF bioreactor. The following day an operative liver failure model was produced by creating a portocaval shunt and ligating the entire hepatoduodenal ligament in the porta hepatis. Perfusion treatment was initiated 4 h after operative induction of liver failure and continued for about 1 h. The pigs which underwent perfusion treatment showed significant improvements in survival and blood data, including ammonia, total bile acid, glucose, and prothrombin time, attributed to significant improvements in the post- as compared to the pre-bioreactor levels in the perfused blood of the treated pigs. These beneficial effects of the NWF bioreactor were based on its excellent composition which allows the accommodation of adequate numbers of hepatocytes and direct contact between hepatocytes and perfused blood.