Background: Coarctation of the aorta (CoA) can be treated using surgery, balloon angioplasty or stent implantation. Although short-term results are excellent with all three treatment modalities, long term cardiovascular (CV) morbidity and mortality remain high, likely due to persistently abnormal vascular function. The effects of treatment modality on long term vascular function remain uncharacterized. The goal of this study is to assess vascular function in this patient population for comparison among the treatment modalities. Methods: Vascular function in large and small arteries will be prospectively assessed fusing multiple non-invasive modalities, and the results will be compared among the three groups of CoA patients previously treated using surgery, balloon angioplasty or stent implantation after frequency matching for confounding variables. A comprehensive vascular function assessment protocol was created to be used in 7 centers. The primary outcome is arterial stiffness measured by arterial tonometry. Inclusion and exclusion criteria were carefully established after consideration of several potential confounders. Sample size was calculated for the primary outcome variable. Conclusions: Treatment modalities for CoA may have distinct impact on large and small arterial vascular function. The results of this study will help identify the treatment modality that is associated with the most optimal level of vascular function, which, in the long term may reduce CV risk.