Liver atrophy is frequently found at autopsy of patients with fulminant hepatic failure (FHF). Imaging studies in patients with FHF demonstrate that estimation of total liver volume correlates with prognosis. In this study, in order to determine serum markers for evaluating liver atrophy, we measured the weight of whole livers resected from 31 transplant recipients with FHF, and assessed the relation between the liver weights and several prognostic markers. The level of liver atrophy was evaluated by calculating the ratio of the removed whole liver weight to the body weight of each recipient, and 16 major variables including several serological markers were analyzed among those recipients. We found that the serum Lens culinaris agglutinin-A-reactive alpha-fetoprotein (AFP-L3) levels were significantly higher in patients with FHF than in those with other liver diseases. In FHF patients, the serum AFP-L3 level at the onset of encephalopathy was significantly higher in cases with mild atrophy than in those with severe atrophy (P<0.05). Notably, the residual liver volume was significantly correlated with the serum AFP-L3 level (Pearson's correlation coefficient=0.63), but not with AFP. In conclusion, AFP-L3 is a possible serum marker for evaluating liver atrophy and/or liver regeneration in patients with FHF.