The follow-up of medically treated acute aortic syndromes relies on CT and MR imaging. Comparison with prior examinations is essential. For aortic dissections, progressive enlargement of the false lumen, visceral hypoperfusion, and extension should be excluded. Mural hematomas and ulcers also undergo close follow-up to detect progression and recanalization. It is important to be familiar with the risk factors of disease progression for medically treated acute aortic syndromes and their management. It is also important to be familiar with the imaging features of disease progression. Acute aortic syndromes managed medically should undergo routine follow-up with CT or MR because these lesions may evolve silently over time and present with complications.