BACKGROUND Aortic coarctation (CoA) is usually confused with interrupted aortic arch (IAA), especially adult type A interrupted aortic arch, due to their similar anatomical location. Although the main difference between them is whether arterial lumen exhibits continuity or not, the clinical manifestations are similar and connection exists between them. Adult type A IAA is considered as an extreme form of CoA, which is complete discontinuity of aortic function and lumen caused by degenerative arterial coarctation. This paper reports two cases (interrupted aortic arch and severe aortic coarctation) to analyze the difference and similarity between them. CASE SUMMARY The two cases of patients presented with hypertension for many years. Computed tomography angiography showed that the aortic arch and descending aorta were discontinuous or significantly narrowed with extensive collateral flow. The IAA patient refused surgical treatment and blood pressure could be controlled with drugs. While the CoA patient underwent stent implantation because of uncontrollable hypertension, the blood flow recovered smoothly and the blood pressures at both ends of the stenosis returned to normal after surgery. CONCLUSION Adult type A IAA and CoA have difference and similarity, and type A IAA is associated with CoA to a certain extent. The treatment method should be chosen based on the patient's clinical symptoms rather than the severity of the lesion.