Survival rates of patients with acute liver failure (ALF) without transplantation are poor. Supporting these patients until an organ becomes available or until their own liver is able to regenerate itself, avoiding transplantation, is a major goal in the treatment of ALF. We report our clinical experience of portal vein arterialization in one case of massive liver necrosis after liver transplantation and in two patients with ALF caused by idiosyncratic drug reaction and mushroom intoxication. Portal vein arterialization, at least in two cases, was a turning point in the course of the disease since a close temporal association between surgery and clinical improvement was clearly evident. We believe that this novel approach, which should promote liver regeneration by providing an additional oxygen supply to the liver, may disclose a new possibility in the treatment of ALF and prompt new clinical and experimental research.