The aim of this study was to investigate the role of donor bone marrow cells infusion in post transplantation anti-HLA antibody induction and outcome of kidney allograft patients. Between June 2006 and May 2007, a total of 40 living donor kidney transplants; 20 recipients with Donor Bone Marrow Cells (DBMC) infusion (2.1×109±1.3×109 MNCs/body including 3.5×107±1.6×107 CD34+ progenitor cells) and 20 without infusion as control, were entered into study and followed prospectively for one year. Both groups received the same baseline immuno­suppressant consisting triple drug regimen. WBC cross match, Panel Reactive Antibody (PRA) and HLA-DNA typing were performed for all patients. Pre and post transplant (days 14, 30, and 90) sera samples were screened for the presence of anti-HLA antibodies, and subsequently antibody identification was determined for positive patients by ELISA method. Incidence of acute rejection (AR) was 30% (6/20) in controls versus 15% (3/20) in DBMI patients. Almost all patients with AR had a pre-transplant anti-HLA antibody in both groups. 35% in DBMI and 30% in controls had pre-transplant antibodies but without acute rejection. In controls, 2 patients with AR and 2 without AR were positive for both Donor Specific Antibody (DSA) and non DSA. All 3 patients with AR in DBMI showed non DSA post operatively, but with a lower strength to HLA antigens. Mean percentages of post transplant PRA was 16.5% vs. 38.5% in controls. The lower titer of antibodies and lower average serum creatinine (2.25±0.07 vs. 2.85±1.2, P=0.0001) were found for patients with AR in DBMI compared to controls. In conclusion, Infusion of DBM mononuclear cells were perfectly tolerated, but the descending rate of creatinine level was slower than control group. The absence of GVHD and lower percentages of PRA in DBMI group are possible manifestations of functional immune modulation achieved by the DBMC infusion protocol.