BACKGROUND AND AIMS: Various techniques of hepatocyte transplantation were actively studied as the alternatives to liver transplantation because of potential advantages including technical simplicity, low risk of operation and use of cells from a liver of single donor for multiple recipients, We investigated the effect of allogenic hepatocellular transplantation into spleen on the survival rate after 90% partial hepatectomy-induced acute hepatic failure in rats. METHODS: Acute hepatic failure was induced by resection of all lobes except caudate lobe in Sprague-Dawley rats. Hepatocytes, isolated by collagenase perfusion of the liver via the portal vein, were transplanted into the spleen of rats after 90% partial hepatectomy (2.0*107 hepatocytes/rat). RESULTS: There was significant difference in the survival rate between control group without treatment after 90% partial hepatectomy and transplanted group receiving intrasplenic allogenic hepatocellular transplantation after 90% partial hepatectomy. Engraftment and survival of transplanted hepatocytes were observed in spleen 2 days after transplantation. Conclusioas: We could observe significant improvernent of survival rate by intrasplenic hepatocellular transplantation in rats with 90% partial hepatectomy-induced acute liver failure. These results suggest that intrasplenic hepatocellular transplantation may be effective in the treatment of acute liver failure.