This report focuses on the effects of tonsillectomy on the improvement of renal function in children with IgA nephropathy, purpura nephritis, or other chronic glomerulonephritis. Tonsillectomies were done on 21 patients, 3 to 13 years of age, who had been diagnosed as one of these nephritides by renal biopsy findings (operation group). Eighteen age-matched controls who also underwent renal biopsy received medication only (non-operation group). For the evaluation of renal function we performed urinalysis for red blood cell count and protein content before and 1 year after surgery in the operation group, and at the first visit to our clinic and 1 year after the medical treatment in the non-operation group. In the operation group, 5 of the 8 cases with IgA nephropathy showed a decrease in both hematuria and the level of proteinuria. Three of 5 with purpura nephritis and 5 of 8 with other glomerulonephritis showed the same results. In the non-operation group, those showing improvement in both hematuria and proteinuria were 1 of 7 patients with IgA nephropathy, 3 of 6 with purpura nephritis, and 1 of 5 with other glomerulonephritis. The results suggest that tonsillectomy may deserve more attention as a treatment modality for nephritis; new indications for the procedure need to be established.