A retrospective case-control study of 71 patients with IgA nephropathy was performed to evaluate the long-term prognostic effect of tonsillectomy. Forty-one patients (19 males and 22 females) underwent tonsillectomy (Group A) and 30 patients (13 males and 17 females) did not (Group B). These patients were followed for more than 10 years after renal biopsy. The average age at the initial renal biopsy was 29.78 years in Group A and 33.0 years in Group B. The average follow-up period was 13 years and 3 months in Group A, and 12 years and 7 months in Group B. Glomerular damage demonstrated on renal biopsy was more extensive in Group A than in Group B. Renal prognosis after 10 years of follow-up was compared between these two groups. The clinical remission rate was 24.4% in Group A and 13.3% in Group B; the stable renal function rate was 82.9% in Group A and 70.0% in Group B; and the renal survival rate was 95.1% in Group A and 73.3% in Group B. The renal survival rate in Group A was significantly higher than that in Group B (p < 0.05). (C) 2003 Elsevier B.V. All rights reserved.