AbstractGranzyme B (GZMB) and perforin 1 gene (PRF1) are key effector molecules of cytotoxic T lymphocytes, in causing acute and chronic solid organ transplant rejection. In this study, we analyzed the impact ofGZMBandPRF1 polymorphism on kidney allograft outcomes. In all, 527de novokidney Hispanic allograft recipients were genotyped forPRF1 (rs10999426, rs35947132) andGZMB(rs8192917, rs7144366).PRF1 (rs10999426, rs35947132) G alleles andGGgenotypes were negatively associated with allograft rejection, demonstrating protection against allograft rejection (OR = 0.61, p = 0.005 for rs1099946;OR = 0.4, p = 0.01 for rs 35947132). On the other hand, theGAheterozygosity ofPRF1 was found marginally associated with the rejection group (OR = 1.53, p = 0.05 for rs10999426;OR = 2.24, p = 0.07 for rs35947132). There was a significant increase in allograft survival in time period studied for thePRF1 (rs10999426)GGgenotype, while theGAheterozygosity was associated with graft failure. We found no association for polymorphic markers inGZMBgene with allograft rejection. Survival was significantly improved for patients who were homozygousTTfor theGZMB(rs8192917) (TTvs.CC/TT, p = 0.041). The result suggests thatPRF1 andGZMBgene polymorphisms may determine the incidence of acute rejection or graft survival among Hispanic allograft recipients.