Although the clinical benefits of antiviral treatment in the management of membranous nephropathy (MN) in patients with chronic hepatitis B virus (HBV) infection have been suggested, it should be evaluated more carefully. In this report, we present two cases with quiescent HBV who were administered lamivudine for either the initial treatment of MN or to control the reactivation of HBV during treatment with corticosteroids. No clinical benefit of lamivudine as an initial treatment was observed in one patient, which obliged us to commence administration of prednisolone (PSL). On the other hand, lamivudine seemed to play a pivotal role in the remission of an acute exacerbation of hepatitis B during treatment with PSL and mizoribine in the other patient. These two patients seemed to tolerate administration of PSL with or without an immunosuppressive agent well, since gradual and prompt improvements of nephrotic status were confirmed within a few months, thus suggesting the potential benefit of steroid treatment. There is little consensus regarding the optimal choice of steroids and immunosuppressants for the treatment of MN with chronic HBV infection, due to the potential for stimulation of viral replication and precipitation of hepatic flares. Our observations, however, suggest that treatment with PSL still should be reserved for quiescent HBV carriers with MN. Further studies will be required to determine the optimal timing and appropriate duration of antiviral treatment in such patients requiring long-term immunosuppression.