HLA-A, -B, and -DR antigens were examined in 71 patients with primary biliary cirrhosis (PBC) enrolled in a randomized, double-blind trial of colchicine versus placebo. All patients had typical laboratory and histological features of PBC, except that six had a negative test for antimitochondrial antibody. Frequencies of these antigens were compared with the international Caucasian panel of the Eighth International Workshop and with a local Caucasian panel. Antigen frequencies were compared using the chi 2 test, with a correction for the number of antigens tested. The PBC patients had a significant excess of DR4 (29 of 70 typed, or 41.1%) compared to the international (804 of 3811, or 21.1%, corrected p value less than 0.05) but not the local panel (47 or 129, or 36.4%). Of PBC patients, 52.9% had only one DR antigen identified, compared to 67.5% for the international panel and 49.6% for the local panel. In past studies, the HLA antigen most strongly correlated with PBC was DR8, but this was not included in our panel of antisera. However, no significant relationship between HLA and PBC was found among the antigens screened.