Chemical dissolution of cholesterol gallstones using ursodeoxycholic acid (UDCA) in six patients with histologically confirmed HBsAg-negative chronic active hepatitis was started after a minimum of one year of therapy with steroids, azathioprine, or chloroquine and a treatment-free period of 8-15 months. The treatment with UDCA lasted 3-20 months with a daily dose of 8-11 mg/kg. Four patients served as controls. A decrease in transaminases (P less than 0.05) occurred in all patients during the UDCA therapy. After completion of the treatment, the figures rose again, but did not return to the initial value. The stones dissolved in five patients. A second liver biopsy was carried out in two patients after UDCA therapy, and this showed no detectable deterioration. Four patients refused biopsy because the laboratory parameters had improved under UDCA. A stone recurred in one patient six months after the end of therapy; the others have remained free of stones for up to 24 months.