Endovascular aneurysm repair (EVAR) of the abdominal aortic aneurysms is an attractive alternative to open surgery with significantly improved perioperative outcomes. However, EVAR is accompanied by a higher rate of graft-related complications and secondary interventions. Therefore, life-long surveillance and management of secondary treatment is essential for successful EVAR. Endoleaks are one of the most crucial problems after EVAR. Persistent endoleaks are classified into five types and its management depends on the type and severity. Most persistent endoleaks are detectable by contrast-enhanced computed tomography; however, in some cases, two different endoleak types may coexist. Determining whether an endoleak requires any treatment or not is an important consideration. Most if not all type I and III endoleaks require prompt and definitive secondary treatment. While type II endoleaks are most commonly encountered during follow-up, not all type II endoleaks require invasive treatment. When secondary treatment is required, it can be treated endovascularly in most cases, even if there is no endoleak. Following EVAR, due to the decompression of the sac, the integrity of the aneurysmal wall strength reduces. Therefore, sudden sac expansion/rupture may occur when an endoleak is encountered following a period of complete aneurysmal exclusion. If diagnosed promptly most late complications can be treated in a less invasive manner, but it could lead to catastrophic event if it is missed. Therefore, adequate and life-long radiographic follow-up is as important as the appropriate patient and device selection as well as the EVAR procedure itself.