The ABCB1 gene encodes the P-glycoprotein (P-gp) that drives the transmembrane efflux of many drugs. The donor ABCB1 polymorphisms have been related with chronic histological damage and long-term renal function among kidney transplanted patients who received cyclosporine A and tacrolimus (Tac). The aim of our study was to determine whether the donor ABCB1 3435 C/T genotype was related with renal function among Tac-treated renal transplanted patients. Kidney donors (n=65) and recipients (n=90) were genotyped for the ABCB1 rs1045642 (c.3435 C/T) and CYP3A5 rs776746 single-nucleotide polymorphisms. The estimated glomerular filtration rate (eGFR) was calculated with the modification of diet in renal disease formulae at five post-transplant times (2 weeks and 1, 3, 6 and 12 months). The recipient ABCB1 and CYP3A5 genotypes had no significant effect on the eGFR at all the post-transplant times. We found significantly lower eGFR values among patients who received a kidney from ABCB1 3435 T carriers (P<0.01). In conclusion, our study confirmed the potential impact of the donor ABCB1 3435 genotype on the post-transplant renal function among patients treated with Tac.