Background: Endovascular aortic repair (EVAR) using stent-graft has shown appropriate and valid treatment in selected patients with complicated or progressive acute aortic syndrome. However, there is little data about regression pattern of aortic lesion after EVAR. Methods: From January 2007 to May 2010, 29 patients who underwent EVAR due to complicated or progressive acute aortic syndrome were enrolled. The underlying aortic syndrome included an intramural hematoma (IMH, n = 15), aortic aneurysm (AA, n = 9) and Stanford type B aortic dissection (AD, n = 5). We analyzed the changes in maximal diameter of aorta, minimal diameter of inner lumen, maximal thickness or lumen size of hematoma, aneurysm and pseudo-lumen before and after EVAR by the use of 64-multidetector computed tomography (MDCT). Then, we defined > 75% of shrinkage in maximal thickness or size of pathologic lesions after EVAR as complete, 25-75% as partial and < 25% as no regression. Results: EVAR was technically successful in all patients. The follow-up 64-MDCT data was obtained at 12-month after EVAR (mean 10.8 짹 1.1 months), and the rate of follow-up 64-MDCT was 89.7%. Lesion characteristics after EVAR described in Table. Conclusion: EVAR in complicated or progressive AAS promotes the regression of main aortic disease through stabilizing further evolution of underlying pathology and maintaining inner luminal space. Also, EVAR achieves the high rate of complete regression in patients with IMH.