The presence of autoantibodies in the serum of 110 patients with primary biliary cirrhosis (PBC), 50 with HBsAg negative chronic active hepatitis (HBsAg- CAH) and 30 with HBsAg positive chronic active hepatitis (HBsAg+ CAH) was assessed using two methods: indirect immunofluorescence on cells grown in tissue culture (HEp-2 cell line) or standard mouse tissue sections, and counter immunoelectrophoresis (CIE) with soluble tissue extracts. Anti-nuclear antibodies (ANA) were found in 38% of sera from patients with PBC using HEp-2 cells compared with 10% using mouse tissue. A variety of staining patterns were detected including a pattern of multiple nuclear dots. In contrast, ANA was detected in 70% of sera from patients with HBsAg- CAH and 27% with HBsAg+ CAH. Using CIE four distinct antibody antigen systems were detected: Ro (SS-A), La (SS-B) and two new systems, designated XH and XR, reacting with extracts of human spleen and rabbit thymus, respectively. Correlation of the presence of antibody with clinical conditions confirmed the close association between anti-centromere antibody and sclerodactyly in patients with PBC and indicated an association between 'multiple nuclear dot' staining and the sicca syndrome in PBC. No association was found between the presence of either Ro or La antibody and the sicca syndrome in patients with PBC.