Postimplantation syndrome (PIS) is the clinical and biochemical expression of an inflammatory response following endovascular repair of an aortic aneurysm (EVAR). The goal of this review is to provide an update on the inflammatory response after endovascular repair of abdominal aortic aneurysm, discussing its causes and effects on the clinical outcome of the patient. PIS concerns nearly one-third of patients after EVAR. It is generally a benign condition, although in some patients it may negatively affect outcome. The different definitions and conclusions drawn from several studies reveal that PIS needs to be redefined with standardized diagnostic criteria. The type of the endograft's material seems to play a role in the inflammatory response. Future studies should focus on a better understanding of the underlying pathophysiology, predictors, and risk factors as well as determining whether effective preventive strategies are necessary.