BACKGROUND: Several studies, including three randomized controlled trials (RCTs), have shown that endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) offered better early results than open surgical repair (OSR) but a similar medium-term to long-term mortality and a higher incidence of reinterventions. Thus, the role of EVAR, most notably in low-risk patients, remains debated. METHODS: The ACE (Anevrysme de l'aorte abdominale: Chirurgie versus Endoprothese) trial compared mortality and major adverse events after EVAR and OSR in patients with AAA anatomically suitable for EVAR and at low-risk or intermediate-risk for open surgery. A total of 316 patients with >5 cm aneurysms were randomized in institutions with proven expertise for both treatments: 299 patients were available for analysis, and 149 were assigned to OSR and 150 to EVAR. Patients were monitored for 5 years after treatment. Statistical analysis was by intention to treat. RESULTS: With a median follow-up of 3 years (range, 0-4.8 years), there was no difference in the cumulative survival free of death or major events rates between OSR and EVAR: 95.9% ± 1.6% vs 93.2% ± 2.1% at 1 year and 85.1% ± 4.5% vs 82.4% ± 3.7% at 3 years, respectively (P = .09). In-hospital mortality (0.6% vs 1.3%; P = 1.0), survival, and the percentage of minor complications were not statistically different. In the EVAR group, however, the crude percentage of reintervention was higher (2.4% vs 16%, P < .0001), with a trend toward a higher aneurysm-related mortality (0.7% vs 4%; P = .12). CONCLUSIONS: In patients with low to intermediate risk factors, open repair of AAA is as safe as EVAR and remains a more durable option.