The number of elderly patients in hemodialysis has increased in recent years and nowadays there are significant numbers of nonagenarians. However, there is currently no information in the literature about arteriovenous fistula (AVF) outcomes in patients aged over 90 years after endovascular treatment for stenosis or thrombosis. This retrospective analysis of prospectively collected data included 38 consecutive patients aged over 90 years who were referred for endovascular evaluation and treatment of AVF nonmaturation (n = 11), dysfunction (n = 25), or thrombosis (n = 2) between 2005 and 2013. Median age was 93.9 years, and 24% were diabetic and 47% hypertensive patients. Immature and dysfunctional AVFs were treated by angioplasty, thrombosed fistulas by thromboaspiration. Fistula patency rates were calculated according to the Life-Table method. The immediate overall clinical success rate was 97.4%. Complications included four transient dilation-induced ruptures. Stents were placed for rupture control (n = 3) and major elastic recoil (n = 3), and to rectify a basilic vein pseudoaneurysm developed after dilation. Mean follow-up was 62.6 months. Primary patency rates were 60% and 43% at 1 and 2 years, respectively. Secondary patency rates were 95% and 92% at 1 and 2 years, respectively. Patency rates were not significantly different between immature and dysfunctional AVFs. Endovascular treatment of AVF complications appears to be a valuable approach in nonagenarian patients in view of the low invasiveness, low complication rate, and relatively good long-term patency rates.