To investigate the clinicopathological characteristics of IgA nephropathy (IgAN) recurrence after renal transplantation and its prognosis. One hundred and forty-eight recipients with pathologically confirmed IgAN as the primary cause of end-stage renal failure who received kidney transplantation between January 1996 and April 2009 were selected from the National Kidney Disease Clinical Medical Research Center. The patients were divided into IgAN recurrence group (46 cases) and non-IgAN recurrence group (102 cases) according to whether they had IgAN recurrence after renal transplantation. The incidence of histological damage to the transplanted kidney and the survival rate of the transplanted kidney were compared between the IgAN recurrence group and the non-IgAN recurrence group at 0, 1, 2, 3 and 5 years after renal transplantation. Results The U-RBC count and 24-h urine protein quantification gradually increased and renal function gradually deteriorated after renal transplantation in the IgAN recurrence group. Compared with the non-IgAN recurrence group, the U-RBC count was significantly higher in the IgAN recurrence group 2-3 and 5 years after surgery, and the renal function was significantly worse at 5 years after surgery (all P<0.01 to 0.001). The results of transplant kidney pathology showed that the incidence of cellular crescent formation, glomerular adhesions, thylakoid cell hyperplasia, increased thylakoid stroma, sphericity, glomerular segmental sclerosis, glomerular abandonment and interstitial fibrosis were significantly higher in the IgAN recurrence group compared with the non-IgAN recurrence group (all P<0.001). chronic transplant kidney injury in the IgAN recurrence and non-IgAN recurrence groups The rates of graft survival were 93.8% and 95.6% (P>0.05) at 1 year, 86.7% and 88.3% (P>0.05) at 3 years, and 51.4% and 83.8% (P<0.001) at 5 years in the IgAN relapse and non-IgAN relapse groups, respectively. Loss of the transplanted kidney occurred in 10 (22%) patients in the IgAN recurrence group and in 9 (9%) patients in the non-IgAN recurrence group. CONCLUSION: Recurrence of IgA nephropathy after renal transplantation is characterized by asymptomatic microscopic hematuria, proteinuria, and progressive decline in renal function, which decreases the long-term survival of the transplanted kidney and suggests a poor prognosis.