Abstract Acute graft pyelonephritis is a very common infection in renal transplantation. The impact of acute graft pyelonephritis (AGPN) on graft and patient outcome has not yet been established. Eight hundred seventy kidney and kidney-pancreas transplants were retrospectively studied, over last 13 years, to verify occurrence of AGPN in the first 30 days post-transplantation. We found that 112 patients (15.8%) presented post-transplantatiom AGPN up to 30 days after a kidney transplantation. The occurrence was higher in older patients ( P  = .005) and in those with ureteral stents ( P  = .06). Escherichia coli was the most frequent microorganism in urine cultures (32%). Ureteral stent (relative risk = 1.7; confidence interval CI, 1.1–2.5; P  = .018) was a major risk factor for AGPN as well as older ages (RR = 1.02; CI 1.01–1.04; P  = .001), length of hospitalization stay (RR = 1.01; CI, 1.01–1.02; P  < .001), and anti-thymocyte globulin (ATG) induction (RR = 1.6; CI, 1.022–2.561; P  = .04). Long-term graft and patient survival was significantly lower in patients with pyelonephritis in the first 30 days after transplantation (OR 1.43; 95% CI, 0.95–2.16; P  = .024 and OR 1.77; 95% CI, 1.12–2.80; P  = .006, respectively). Acute pyelonephritis in the first 30 days after transplantation is therefore associated with a lower long-term graft and patient survival.