AIMS: This study reports long-term outcomes after endovascular salvage (EVS) for acute dialysis fistula/graft dysfunction. METHODS: All patients presenting with acute fistula or graft dysfunction, excluding primary failures, referred for endovascular salvage were included in this single-centre prospective study. RESULTS: Altogether, 410 procedures were carried out in 232 patients. Overall, the incidence of thrombosis/occlusion (per patient-year) was 0.12 for fistulae and 0.9 for grafts. The anatomical success rate for EVS was 94% for fistulae and 92% for grafts. Primary patency rates for fistulae at 1, 6, 12, 24 and 36 months were 82, 64, 44, 34 and 26%, respectively, whereas secondary patency rates were 88, 84, 74, 69 and 61%, respectively. Primary patency rates for grafts at 1, 6 and 12 months were 50, 14 and 8%. The overall rate of complications was 6% with no incidence of symptomatic pulmonary embolism. In a Cox regression model, upper-arm location of fistula (HR 1.9, p = 0.04, n = 144) was associated with lower primary patency, whereas the presence of thrombosis was associated lower primary (HR 1.9, p = 0.004, n = 144) and secondary patency (HR 3.7, p <0.001, n = 144). Aspirin therapy was associated with longer primary patency (HR 0.6, p = 0.02, n = 144) and secondary patency (HR 0.58, p = 0.08, n = 144). CONCLUSION: EVS is effective but longer-term outcomes are poor. Presence of thrombosis portends poor fistula survival and strategies for prevention need attention. Balloon maceration, our preferred declotting technique, is safe and the most cost-effective method. Aspirin therapy for patients presenting with failure of fistulae deserves further investigation.