Seventeen patients with chronic active type B hepatitis were treated with prednisone for 4 weeks. All were initially hepatitis B e antigen (HBeAg)-positive and 14 were DNA-polymerase-positive as well. In the follow-up period of 1 year, 10 patients became persistently negative for DNA polymerase and 11 cleared HBeAg from serum, while among 17 matched untreated controls only one lost DNA polymerase and HBeAg. However, 1 patient who was initially DNA-polymerase-negative and who lost HBeAg after treatment reactivated to HBeAg after 4 months and DNA polymerase appeared in his serum. He suffered prolonged exacerbation of liver disease after treatment and died of liver failure. Short-term corticosteroid therapy may be of value in patients with chronic active type B hepatitis, however, in some cases such treatment may be disastrous.