In 22 children with severe acute viral hepatitis, the course of the disease followed 3 patterns: 8 children completely yielded (regenerative hepatitis); 8 died during the first three weeks of evolution (aregenerative hepatitis); 8 had a prolonged evolution (hyporegenerative hepatitis). In the latter group, 6 patients died after an average survival time of 55 days and 2 patients rapidly developped a cirrhosis. This type of evolution was characterized by persistence of liver failure manifestations, in spite of liver regeneration, as indicated by increased levels of alpha-foetoprotein and presence of pseudo-acini, giantcells and nodules at histological examination. During the second week of evolution, the size of liver, levels of clotting factors VII +X and alpha-foetoprotein concentrations seem to constitute important prognostic factors.