Autoimmune chronic active hepatitis is traditionally treated with corticosteroids, or corticosteroids with azathioprine. These drug therapies require long treatment periods and are associated with many debilitating drug side effects. Five patients with type I autoimmune chronic active hepatitis, and one with a probable overlap syndrome were treated with cyclosporine. All patients had previously undergone treatment with corticosteroids or corticosteroids with azathioprine and had failed to achieve total remission. In addition, all patients had significant side effects associated with therapy. Five of six patients normalized or near normalized alanine aminotransferase levels within 10 weeks of starting cyclosporine therapy. Biochemical remission was sustained for periods of up to 1 year in all primary cyclosporine responders as long as therapeutic cyclosporine levels were maintained. All responders had symptomatic improvement. Post-treatment liver biopsy was performed in three patients and histologic improvement was demonstrated in all cases. Cyclosporine appears to be a viable alternative to corticosteroid/azathioprine therapy for autoimmune chronic active hepatitis in patients who experience an incomplete response or who cannot tolerate the side effects of standard therapy.