In this study, the effect of lamivudine therapy on viral suppression, Child-Pugh score, and survival was assessed in patients with decompensated cirrhosis due to precore mutant hepatitis B virus and the results were compared with those for nonreplicative cirrhotic patients. Twenty-three replicative patients who received lamivudine and 15 nonreplicative patients were included and followed up for an average of 23.7 +/- 13.4 months. At baseline, there were no significant differences between the groups with regard to clinical and biochemical parameters or Child-Pugh scores, except for serum alanine aminotransferase levels (P < 0.05) and quantitative hepatitis B virus DNA measurements (P < 0.001). Compared to baseline, there was no significant difference in Child-Pugh score in the lamivudine group at the last visit (P = 0.202), whereas a marked increase was observed in nonreplicative patients (P = 0.002). Mortality rates in the lamivudine and nonreplicative groups were 17.43% and 13.3%, respectively (P = 0.556), and there was no difference in survival analysis (P = 0.809). Lamivudine therapy stabilizing clinical situation in decompensated cirrhotics with precore mutation makes the natural history of the disease equal with nonreplicative decompensated cirrhotics or even provides some advantages over them.