Patients with primary biliary cirrhosis have an abnormally high incidence of urinary tract infection (35%). Susceptibility to urinary infection and other infectious diseases has been linked with certain blood group antigens and secretor status. We have therefore studied these characteristics in patients with primary biliary cirrhosis. We were unable to show any abnormal distribution in blood groups or secretor status in patients with primary biliary cirrhosis (compared with a normal population) which might reflect their predisposition to urinary infection. The distribution of blood groups and secretor status in patients with primary biliary cirrhosis with a history of urinary infections was not significantly different from patients without such a history. Escherichia coli strains isolated from patients with primary biliary cirrhosis did not bind in any greater numbers to the uroepithelial cells of primary biliary cirrhosis patients than to the cells of a normal healthy control. We therefore conclude that blood group distribution, abnormal secretor status, and epithelial cell type are not important factors in the predisposition of primary biliary cirrhosis patients to urinary infections.