To identify features reflective of early prognosis in corticosteroid-treated severe autoimmune chronic active hepatitis, we compared the initial findings and immediate biochemical response of 5 patients who died soon after institution of corticosteroid therapy (mean survival, 2.5 +/- 0.7 mo) with those of 108 patients who survived for at least 6 mo after comparable therapy (mean survival, 94 +/- 6 mo). Early mortality could not be predicted before therapy by individual clinical, laboratory, or histologic findings. Patients who resolved at least one pretreatment laboratory abnormality, improved a pretreatment hyperbilirubinemia, or did not experience biochemical deterioration after 2 wk of corticosteroid treatment survived for at least 6 mo in 98% of instances. Patients who died early had multilobular necrosis at presentation and manifested at least one deficiency in their immediate biochemical response. Death invariably occurred in patients with multilobular necrosis and an unimproved hyperbilirubinemia after 2 wk of therapy. Only 3 of the 5 patients who died, however, could be identified in this fashion. We conclude that no individual abnormality at presentation predicts early mortality. Only patients with multilobular necrosis are at risk for an early demise and death can be predicted in those with an unimproving hyperbilirubinemia. Laboratory improvement after 2 wk of corticosteroid therapy virtually assures immediate survival.