Chronic allograft nephropathy (CAN) is considered one of the main problems facing successful renal transplantation and has a negative impact on both graft function and survival. Both immunologic and non-immunologic factors share in the pathogenesis of CAN. The final decision about transplantation is based primarily on a negative result of a complement-dependent cytotoxicity cross-match. The significance of a positive flow cytometric cross-match (FCXM) is unclear. The aim of the present work was to study the relation between B and T-cell flow cytometry crossmatch post-renal transplantation and chronic allograft nephropathy. This study was conducted on 40 living kidney allograft recipients, They were classified into 2 groups: Group I: 20 transplanted patients with stable renal functions at least 6 months post-transplantation. Group II: 20 transplanted patients with progressive increase in serum creatinine.The renal transplant recipients were subjected to routine biochemical investigations, viral markers (HBV, HCV, HIV, CMV), and cyclosporin assay. In addition, complement dependent cytotoxicity crossmatch (CDCXM) and B&T-cell flow cytometry crossmatch (FCXM) were done for all patients. For all transplanted patients CDC was negative when done before transplantation and repeated at the time when FCXM was done. T-Cell FCXM and B-Cell FCXM was positive in 20%, 40% of cases in group I and 50% and 60% of cases in group II respectively, but the difference was insignificant. There was a significant positive correlation between serum creatinine and both positive B-cell FCXM and the number of total HLA mismatches in both transplanted groups. We conclude that allo-antibodieas detected by flow cytometry crossmatch after kidney transplantation may have a little risk in the development of chronic allograft nephropathy.