A 57-year-old man presented with nephrotic syndrome associated with active HBV infection. Liver biopsy showed severe portal and moderate lobular inflammation, patchy necrosis, moderate fibrosis and several "ground glass" cells. Immunofluorescence microscopical view of the renal biopsy showed diffuse granular IgG deposits along the glomerular basement membrane, compatible with MN. As symptomatic therapy with ACE inhibitors did not improve the nephrotic syndrome, lamivudine 100 mg o.d. was initiated. HBV-DNA became undetectable after 10 weeks and seroconversion of HBeAg and HBsAg to anti-HBe and anti-HBs occurred after 2 additional months; proteinuria normalized subsequently. This observation documents for the first time in an adult the beneficial effect of lamivudine in glomerulonephritis related to HBV infection with HBV seroconversion and complete remission of the nephrotic syndrome.