Hyaluronan (HA) and aminoterminal propeptide of type III procollagen (PIIINP), two biochemical connective tissue markers, were determined in 76 patients with primary biliary cirrhosis (PBC). The HA and PIIINP concentrations were significantly increased compared with controls (P less than 0.001). Both HA and PIIINP levels correlated significantly with conventional liver-function tests. All patients with stage IV PBC showed increased concentrations of both these variables. However, HA was a better marker with regard to prediction of development of cirrhosis as well as prediction of symptoms. Furthermore, HA also showed a negative correlation with time of survival (P less than 0.05). The present data indicate that HA is a more sensitive marker of liver damage in PBC than PIIINP.