OBJECTIVE: Reduced hospital stay and intensive care unit stay after endovascular aneurysm repair (EVAR) compared to open repair (OR) of abdominal aortic aneurysms (AAA) are expected to result in reduced costs of AAA repair. The cost and cost effectiveness of OR and EVAR in the first postoperative year were compared in a randomised trial. METHODS: In a multicenter randomised trial comparing OR and EVAR we randomly assigned 149 patients to OR and 151 to EVAR. Complications, costs and cost-effectiveness were determined one year after surgery. The uncertainty surrounding the cost-effectiveness ratios (iCER ) was addressed by bootstrapping. Results. Ten patients had died in the OR group and 9 in the EVAR group (chi-square p=0.8). In the OR group, 32 patients had one or more severe complications and in the EVAR group, 27 patients (chi-square p=0.5). EVAR was associated with €4.480 additional direct costs per patient (€18.138 versus €13.659) and a decrease in QALY of 0.72 as compared with 0.73 (difference 0.01 year, 95% CI -0.04- 0.06). With regard to event free survival over 85% of the bootstrap estimates EVAR indicated favourable health outcomes for EVAR, but against prohibitively higher costs. From a health economic perspective OR is preferred. Conclusion. In patients suitable for both treatments, EVAR is not cost-effective in the first postoperative year.