Liver involvement in patients with primary Sjögren's syndrome is rare, usually without clinical significance and histologically characterized by a feature like stage 1 primary biliary cirrhosis. We describe herein a case of acute and severe autoimmune hepatitis in a patient suffering from primary Sjögren's syndrome. The diagnosis of Sjögren's syndrome was performed in 1989. In June 1995 the patient presented severe weakness, jaundice and elevation of transaminases; moreover IgG raised to 5560 mg/dl and ANA titre increased to 1:20480. The patient denied alcohol and drug use and a viral hepatitis was excluded. Antimitochondrial antibodies, anti-smooth muscle antibodies and antibodies against liver kidney microsomes were negative. An abdomen ultrasound examination revealed hepatomegaly, with irregular echogenic structure and lymphoadenomegaly near the celiac tripod. Liver biopsy demonstrated a picture of autoimmune hepatitis. The patient was treated with prednisone 50 mg/day and azathioprine 50 mg/day, with improvement in clinical and liver function indices. At present, the patient is given only 10 mg/day of prednisone. The association of Sjögren's syndrome with autoimmune hepatitis is very rare: in the literature only one other similar case has been reported.