Chronic active hepatitis (CAH) as an entity covers a histologically, biochemically, and clinically heterogenous group of patients. Hence, there is no justification for treating all patients with this diagnosis with corticosteroids. On the basis of histological, biochemical, and clinical criteria, different degrees of severity of CAH can be distinguished. While corticosteroids appear to be indicated in severe CAH, they should, in general, not be administered in mild CAH. However, the course of disease must be carefully followed in these patients. In moderate CAH, the risk should be carefully weighed against the benefit of therapy in every individual patient, taking into account the severity of symptoms. In HBsAg-negative cases, a therapeutic trial of at least 6 months' duration is worthwhile. In HBsAg-positive patients, treatment with corticosteroids should be delayed and the course of the disease followed. Once the decision for corticosteroid therapy has been made, administration of 10 mg prednisolone and 50 mg azathioprine daily as a maintenance dose represents the therapy of choice. This combination is approximately as effective as 15--20 mg prednisolone alone, but is associated with a lower incidence of side effects.