In a prospective double-blind trial, polyunsaturated phosphatidyl choline therapy (3 g/day) was given in addition to normal maintenance immunosuppressive therapy to 15 patients with HBsAg negative chronic active hepatitis. Histological evidence of disease activity was significantly reduced in the phospholipid-treated group. The results indicate that polyunsaturated phosphatidyl choline is of value as additional treatment in the management of patients with HBsAg negative chronic active hepatitis whose disease is inadequately controlled with conventional doses of immunosuppressive therapy.