Renal allografts with excellent graft function have good long-term outcomes; while grafts with delayed function have been associated with an increased incidence of acute rejection (AR) and subsequent poor long-term graft survival, although few reports have analyzed outcomes in these groups. We compared first week postoperative graft function between various subgroups among renal transplant patients and analyzed the impact of slow graft function (SGF) and delayed graft function (DGF) on graft survival. Renal transplantation was performed on 362 patients receiving kidney from unrelated and 46 from related and 163 from deceased donors. Kidney transplant patients were divided into three groups, according to the initial graft function. First-week dialyzed patients form the DGF group. Nondialyzed patients are divided into SGF or excellent graft function (EGF) according to whether the day 7 serum creatinine was higher versus lower than 2.5 mg/dL, respectively. Graft survival was measured. Statistical analysis was performed using SPSS software, Kaplan-Meier table, and log ranks. Of the 570 renal transplant recipients, DGF was seen in 39 (6.8%) patients, SGF in 64 (11.2%) recipients and EGF in 467 (81.8%) patients and there was no significant difference in slow and delayed graft function between patients who had received kidney from unrelated and related living and deceased donors. Graft survival was worse among DGF than SGF or EGF patients, with no significant difference between the latter two groups (6-month graft survival, 74%, 93%, 96% and 3-year graft survival, 70%, 88%, 90%, respectively; log-rank test, P < .001). Kidney transplant recipients who developed DGF had a worse outcome than patients with EGF, and SGF patients. In conclusion, we found a similar impact of excellent and slow graft function on kidney graft survival, but kidney transplant recipients who develop DGF had a worse graft survival than patients with EGF and SGF.