Purpose: The aim of this study was to document the incidence rate of adverse events after endoluminal repair of abdominal aortic aneurysms (AAA) during two successive periods of time. Methods: One hundred ninety patients (175 men, 15 women; mean age, 72 years) underwent endoluminal repair of AAAs in a 5 1/2-year period. Adverse events were documented prospectively for all the patients throughout this interval. An adverse event was defined as any of the following events: a death within 30 days, a conversion to open repair, the need for further intervention (either open or endovascular), the need for hemodialysis, a failure to cure the AAA, and wound complications. The patients were divided into two groups - those who underwent operation in the initial 3-year period (group I; n = 75) and those who underwent operation in the subsequent 2 1/2-year period (group II; n = 115). The results were analyzed for total adverse events for both periods of time and for difference in incidence rates within categories of adverse events between the two groups. Results: Eight patients (4.2%) died in the perioperative period. The endoluminal repair failed in 17 patients (8.9%), which necessitated a primary conversion to open repair at the original operation. In 88 patients, 110 adverse events occurred. There was no significant difference in the incidence rates of adverse events in patients in group I (37/75) and group II (51/115). Apart from primary conversion (P = .007), there was no significant difference in the incidence rates of adverse events between group I and group II within the following categories: perioperative (within 30 days) deaths, primary conversion, secondary conversion, supplementary endoluminal repair, intervention for lower limb ischemia, hemodialysis necessitated, failure to cure the AAA as a result of persistent endoleak, and wound complications. Conclusion: Despite improvements in technology and increasing experience, adverse events continue to occur in a relatively high proportion of patients (45%) who undergo endoluminal repair of AAA. Reporting the incidence rates of adverse events provides a more accurate picture of the morbidity rates of the endoluminal method rather than simply listing the procedures as successes or failures. The similarity in the incidence rates of adverse events in patients in group I and group II suggests that there are inherent risks in the endoluminal method rather than iatrogenic complications that occur during the learning curve with a new technique.