Despite numerous studies on the effects of bile salts therapy in chronic liver disease, there are no reports on the influence such therapy has on hepatocyte proliferation. The aim of this preliminary study was to evaluate the effect of TUDCA on hepatocyte proliferation in 5 patients with HCV-correlated chronic liver disease. All patients were treated with TUDCA (10-13 mg/day) for three months and the determination of PCNA (Proliferating Cell Nuclear Antigen) expression was used to assess the proliferative activity of hepatocytes at the beginning and at the end of treatment. TUDCA reduced both ALT and Knodell's score in the 5 patients in whom a significant increase of PCNA-LI (p < 0.05) was observed after treatment. TUDCA administration seems to stimulate hepatocyte proliferation in man.