This study was conducted to investigate the relationship between Helicobacter pylori infection and three varieties of glomerulonephritis. Renal biopsy specimens from patients with Henoch Schonlein Purpura nephritis (HSPN; n = 10), membranous nephropathy (MN; n = 9) and lupus nephritis (LN; n = 27) were studied using immuno-histochemical labeling to clarify the etiological significance of H. pylori antigen in this disease. Immuno-histochemical labeling was performed using a mixture of anti-H. pylori-antibody-positive serum from nine volunteers; a mixture of anti-H. pylori-antibody-negative serum from nine volunteers was used as control. Staphylococci protein-A labeled by horseradish peroxidase was used as the second antibody in this study. A total of 34 of the 48 specimens revealed positive reaction with the anti-H. pylori-positive serum and five of the 48 specimens revealed positive reaction with the anti-H. pylori-negative serum. Positive reaction against anti-H. pylori-positive serum was seen in 10/10 patients with HSPN, six of nine patients with MN and 18/27 patients with LN. Statistical analysis showed that the difference of the positive reaction between anti-H. pylori-positive and negative sera was significant (χ 2 = 36.318, P = 0.000). Our study indicates that H. pylori infection may be associated with the development and/or progression of HSPN, MN and LN.