Background: Information regarding the clinical characteristics and outcomes of kidney transplant recipients (KTRs) with > 25 years of graft survival is limited. Methods: In this single-center observational study, we characterized KTRs transplanted between 1973 and 1992 with active follow-up as of July 31, 2017. Results: We identified 112 patients with > 25 years of allograft function. The mean posttransplantation follow-up was 29.8 ± 4.0 years. Glomerulonephritis was the most common cause of end-stage renal disease (ESRD) (52%). The majority received live donor transplants (66%), including 25 patients (22%) with human leukocyte antigen-matched kidneys. The incidence of biopsy-confirmed acute rejection was 21%, ranging from 0 to 26 years post transplantation. Donor-specific antibodies (DSA) were checked in 80% of patients at a mean of 28.4 ± 0.11 years post transplantation. Of these, only 15% were positive. The incidence of malignancy was 44%, with nonmelanoma skin cancers being most common. The incidence of infectious complications was 77%, mostly represented by urinary tract infections. At the time of last follow-up, 63% were on a calcineurin inhibitor (CNI)-free regimen, mean serum creatinine was 1.4 ± 0.6 mg/dL, and the prevalence of hypertension and dyslipidemia was 89 and 88%, respectively. Conclusion: The majority of patients with a long-term functioning graft had glomerulonephritis as cause of ESRD, had received a live donor kidney, were on a CNI-free regimen, and had a low incidence of DSA and opportunistic infections. These characteristics define a unique group of patients requiring specific posttransplantation monitoring and management.