A retrospective study on 247 cases of chronic hepatitis was made. 177 patients with chronic aggressive hepatitis (CAH) were treated with prednisolone, azathioprine, the combination of prednisolone and azathioprine, or D-penicillamine. Prednisolone and the combined therapy was significantly more effective than azathioprine or D-penicillamine. It seems questionable, however, whether the addition of azathioprine to prednisolone is of real advantage.