Abstract Background and Aims Older patients with antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV) commonly experience renal impairment and poor prognosis. The European Vasculitis Study Group trials showed that approximately 16.7% and 22.5% of older patients with AAV suffered from end-stage renal disease (ESRD) in 5- and 10-year durations. The aim of this study was to analyze differences in course and outcome of patients with AAV with respect to age. Method This retrospective observational study included patients with diagnosis of AAV and biopsy proven renal involvement between 2000-2021. Patients were divided into two groups according to age: ≥65 or <65 years old. We recorded baseline characteristics and clinical data during follow-up. Response was defined as a BVAS reduction of at least 50% or BVAS of 0, while receiving prednisone dose higher than 4 mg; and remission as BVAS of 0 while receiving prednisone dose of 4 mg or less. Results We included 42 patients with AAV diagnosis, 47.6% of which were 65 years-old or older. Mean age of the older age group was 77 ± 8 years. No differences were found between older and younger patients at baseline (BVAS, FFS extra-renal symptoms, serum creatinine at diagnosis, hematuria), Patients > 65 years were significantly more likely to present p-ANCA positive MPA, as shown in Table 1. There was no difference in initial or maintenance immunosuppressive therapy between the two groups. No differences were found between older and younger patients with regard to treatment response. Although we found no statistical differences, older patients had worse renal outcomes. The older adult group had a higher mortality rate, p 0.01. The average time to death was 27 months for patients over 65 years and 34.5 in those who were younger (p 0.71). Conclusion No differences were found between older and younger patients with regard to treatment response. However, mortality was higher during follow-up in the group of older patients. Our results suggest that more attention should be paid to older patients with severe renal impairment.