We report long-term results over 10 years in patients developing glomerulonephritis after renal transplantation. The prevalence rate of glomerulonephritis was 6.2% in 785 renal transplants involving 697 patients with end-stage renal disease. This rate was 14% in patients undergoing biopsy of their grafts because of malfunction. The rate was 15% in patients diagnosed as having glomerulonephritis of any cause prior to transplantation. Membranous, focal sclerosing, and IgA glomerulonephritis were the most common histologic diagnoses. Documented histologic recurrence occurred in only 1% of patients with prior, biopsy-proven glomerulonephritis of their native kidneys. Patients with focal sclerosing glomerulonephritis had the greatest risk from recurrence. De novo glomerulonephritis was most likely to be membranous in character. The graft survival rate of patients with glomerulonephritis was not distinguishable from that of patients showing rejection; both were 45% at 60 months and 33% versus 11 %, respectively, at 120 months (P = NS); the graft survival rate in patients without rejection was 76% at 120 months. Thus, glomerulonephritis is responsible for approximately 14% of renal graft malfunction. Glomerulonephritis has a prognosis similar to chronic rejection. Finally, glomerulonephritis as specific histologic recurrence is unusual. Patients with glomerulonephritis should not be discouraged from undergoing transplantation because of putative risks related to recurrence. © 1993, National Kidney Foundation, Inc.. All rights reserved.