We analyzed the impact of antithymocyte globulin (ATG) in renal transplantation. We retrospectively studied 1217 recipients performed from July 83 to December 03. ATG-Fresenius-S (ATG-F) was used for induction therapy in 492 patients (40.4%; group I) and compared with group II, 725 patients (59.6%), without antilymphocyte induction. Groups were comparable in terms of recipient gender and race distribution; time on dialysis; cause of renal disease; number of human leukocyte antigen (HLA) mismatches; donor age, gender, and creatinine; and cold ischemia time. Patients with ATG-F were younger (35.8 +/- 13.8 vs 38.9 +/- 12.5 years, P < .001), more frequently hypersensitized (10% vs 3%, P < .001), and had more second transplants (15.7% vs 5.8%, P < .001). The incidence of acute rejection episodes was lower among ATG-F patients (23.6% vs 32.1%, P = .004). Admission time and incidence of delayed graft function (DGF) were similar in the two groups. Graft survival at 1, 5, 10, and 15 years was 88.9%, 80.7%, 71.3%, and 64.9% in group I and 86.4%, 77.4%, 60.7%, and 48.4% in group II (P = .003). The difference in patient survival over the same follow-up did not reach statistical significance. Multivariate analysis showed that the risk of graft failure was higher for those who did not receive ATG-F (HR = 1.51; 95% CI, 1.14 to 2.00; P = .004). Donor age and DGF were also independent predictors of graft failure. Our results showed a better long-term graft survival among patients who received ATG-F, despite their higher immunological risk. The absence of induction with ATG-F, donor age, and DGF were independent risk factors for graft failure.