A possible role of HBsAg in hepatic glomerulonephritis was evaluated in kidney specimens from 104 patients with various diseases. Huang's method using formalin-fixed and paraffin-embedded sections was applied to the kidney from 65 cases. Only 4 (3.8%) with liver cirrhosis had glomerular HBsAg deposition; 3 on frozen and one on paraffin sections. In one case of crescentic glomerulonephritis, HBsAg appeared to have had a pathogenetic role with glomerular immunofluorescence dominant for IgM, less intense IgG and negative IgA. The glomerular HBsAg in the remaining 3 patients with hepatic IgA glomerulonephritis was likely to be concomitant or superimposed. One of them had a nephrotic syndrome for which corticosteroid treatment was given, resulting in a near-complete remission and disappearance of HBsAg in the glomeruli, but the glomerular immunohistology was unaffected by the treatment. The present findings suggest that HBsAg has only a minor role.