Intracutaneous Kveim test and measurement of serum mitochondrial antibodies were performed in a group of patients with primary biliary cirrhosis (PBC) and in a group of patients with sarcoidosis. There were 14 patients, 1 man and 13 women, age range 39-64 years, with clinical picture, laboratory tests and liver biopsy consistent with PBC. In the sarcoidosis group there were 38 patients, 18 men and 20 women, age range 22-76 years, with clinical, radiological and histopathological findings typical for sarcoidosis. In this group chest x-ray showed stage 0 in 3 patients, stage I in 7, stage II in 18 and 10 patients were in stage III. Kveim test was positive in 24 (63.2%) of the sarcoid patients and negative in all 14 patients with PBC. Mitochondrial antibodies were present in 13 of the PBC-patients but in none of the 38 examined sarcoid patients. Kveim test and analysis of mitochondrial antibodies seems to be of great value in the differential diagnosis between primary biliary cirrhosis and sarcoidosis.