Background. Bioartificial liver may be useful as a bridge to liver transplantation but there are no data of its efficacy in successfully bridging to spontaneous recovery: in fulminant hepatic failure. The aim of our study was to evaluate the efficacy of a bioartificial liver in increasing the spontaneous recovery of pigs with hepatic failure. Methods. The bioartificial liver consisted in a semipermeable: dialyzer with 0.6x10(9) cryopreserved allogenic hepatocytes. Hepatic failure was induced by portacaval shunt plus 70% hepatectomy and 1 hour occlusion of:the hepatic artery, Forty-one pigs were distributed 24 hr after liver failure induction to a group treated with the bioartificial liver (4 hr daily) until recovery or death (n=16), or to a control group (n=25), Intracranial pressure was monitored in 18 additional pigs, before and 4 hr after treatment with the bioartificial liver with (n=12) or without hepatocytes (n=6). Results. Fifteen days after induction of hepatic failure, 44% of the treated animals had survived and recovered from liver failure versus 22% controls (P=0.030). Intracranial pressure decreased from 13.13+/-5.1 to 7.19+/-2.06 mmHg (P=0.02) in treated animals, and remained unchanged in sham-treated animals (14.08+/-1.92 to 12.54+/-3.82, ns). Conclusions. Bioartificial liver increases survival and allows spontaneous recovery in pigs with fulminant hepatic failure.