Background: We aim to determine the reintervention rate after open aortic aneurysm repair (OAR) or endovascular aneurysm repair (EVAR) according to compliance or noncompliance with the instructions for use (IFU) for commercial endovascular stent grafts. Methods: After exclusion of those with a ruptured abdominal aortic aneurysm (AAA) and isolated iliac artery aneurysm with or without a small AAA (diameter < 5 cm), 240 patients received OAR or EVAR for a nonruptured AAA between January 2006 and March 2016. EVAR was performed from October 2009. Patients were divided into 3 groups: OAR (n = 146), IFU EVAR (n = 42), and nonIFU EVAR (n = 52). Reintervention was defined as graftrelated or laparotomyrelated (with an abdominal incision after initial laparotomy) reoperations either during the index admission period or later. Final endoleak after EVAR was defined as persistent type I or III endoleak before exiting operating room after various procedures to eliminate the endoleak. Results: There were 2 inhospital deaths in the OAR group caused by reperfusion injury or pancreatitis. There was no inhospital mortality in the EVAR group. Final endoleak was more common in nonIFU EVAR compared with IFU EVAR (17% vs. 0%; P = 0.004). The mean followup duration was 42.1 months, 25.3 months, and 25.0 months in the OAR, IFU EVAR, and nonIFU EVAR groups, respectively. Respective reinterventionfree survival (RFS) rates at 1 and 3 years differed significantly by group: 97% and 95% in the OAR group, 100% and 96% in the IFU EVAR group, and 89% and 87% for nonIFU EVAR group (P = 0.043) with a higher reintervention rate in the nonIFU EVAR than in the OAR group. There was no significant difference in RFS rate between the OAR and IFU EVAR groups (P = 0.881). Overall survival (OS) rates at 1 and 3 years, respectively, were 94% and 78% in the OAR group, 90% and 86% in the IFU EVAR group, and 93% and 56% in the nonIFU EVAR group (P = 0.098). There were no significant differences between the OAR and IFU EVAR groups (P = 0.890). Conclusions: In contrast to IFU EVAR group, the RFS and OS rates of nonIFU EVAR group were lower than in the OAR group during midterm followup. Final endoleak was more frequent, and reintervention was more commonly performed in the nonIFU group than in the IFU group. Therefore, performing EVAR in nonIFU situations should be planned carefully.