BACKGROUND: It has been well known that the degree of HLA matching in renal transplantation is important in graft and patient survival. Because HLA-identical living-related donor grafts are free from immunological attacks, they have benefits of one immunosuppressants or early withdrawal of steroids. However, there is acute rejection due to early withdrawal of immunosuppressants and graft loss due to recurrent glomerulonephritis following HLA- identical living-related renal transplantation. The purpose of this study is to determine the graft survival and the impact of recurrent glomerulonephritis on graft survival in HLA-identical living-related donor grafts. METHODS: From December 1984 to March 2004, 44 HLA-identical and 80 HLA-haploidentical living- related renal transplants in Bongsaeng Memorial Hospital were included in this study. We evaluated graft survivals, immunosuppressants and causes of graft failure. RESULTS: The mean graft survival for HLA-identical transplants is 198 months (16.5 years) and for HLA-haploidentical transplants is 166 months (13.8 years), respectively (p=NS). Acute rejection episodes occurred in 2 of the 44 (5%) identical transplants and 17 of the 80 (21%) haploidentical transplants, respectively (p=0.013). 6 grafts were lost in HLA- identical transplants and the causes are 4 recurrent glomerulonephritis (66.7%), 2 chronic rejections (33.4 %). 11 grafts were lost in HLA-haploidentical transplants and the causes are 6 chronic rejections (54.5 %), 1 acute rejection (9.1%), 1 drug toxicity (9.1%), 3 patient deaths (27.3%). Recurrent glomerulonephritis in HLA-identical transplants are three, but in HLA-haploidentical transplants are none. CONCLUSION: Our data revealed that there was no difference in graft survival between the two groups, but lower acute rejection rate in HLA-identical groups. Recurrent glomerulonephritis was the main cause of graft failure in HLA-identical groups and the impact of recurrent disease on graft survival needs to be investigated.