The study analyzed factors associated with 25-year kidney transplant survival in a single-center cohort, comparing 59 patients with ultra-long survival (ULS, ≥25 years) and 61 with early failure (EGF, ≤10 years). Cold ischemia time was shorter in ULS (1281.8 ± 473.9 min) than in EGF (mean difference 483 min, p=0.016), and every 60 min increased the odds of EGF (adjusted OR 1.29; 95% CI 1.02–1.63; p=0.032). In the first year, ULS had fewer antirejection treatment cycles (≥1 in 40.7% vs. 63.9%; p=0.017). Renal function was better in ULS: lower creatinine at 6 months, 1 year and 5 years (all p≤0.004) and higher hemoglobin at 5 years (p<0.001). Exploratory analyzes confirmed the association with ischemia time and rejection burden; 6-month creatinine levels discriminated EGF vs. ULS (AUC 0.739). The results are observational and residual confounding cannot be ruled out.