To report the frequency of endoleaks after endovascular aneurysm repair (EVAR) with the AneuRx graft. The study group included 121 consecutive patients treated with the first-generation AneuRx graft before December 2005, which ensured a potential minimum follow-up of 5 years. Thirty-seven patients (31%) had 45 different endoleaks at varying times in their follow-up. There were 18 type I endoleaks (15%), 56% of which developed more than 5 years after EVAR. All 12 type Ia endoleaks were associated with dilation of the neck of the aneurysm by a mean of 8.5 mm at a median follow-up of 4 years. Ten of the 12 type Ia endoleaks were judged to have very favorable necks for EVAR. Five additional patients being followed had documented neck dilation and/or migration without evidence of endoleak or aneurysm enlargement. All type II endoleaks were noted in the first 2 years, and one persisted untreated for 9 years. Type I endoleaks continue to appear over time, and 56% occurred at 5 years or later after EVAR. All were associated with dilation at the attachment site, and all type Ia endoleaks had migration. As type Ia endoleaks may not always be amenable to endovascular repair, EVAR should be considered a less attractive option for some patients whose life expectancy is predicted to exceed 10 years.