Nontraumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy, and management. There is a common pathway for the various manifestations of AAS that eventually leads to a breakdown of the aortic intima and media. Improvements in biology and health policy and diffusion of technology into the community resulted in an associated decrease in mortality and morbidity related to aortic therapeutic interventions. Hybrid procedures, branched and fenestrated endografts, and percutaneous aortic valves have emerged as potent and viable alternatives to traditional surgeries. In this context, current state-of-the art MDCT is actually the gold standard in the emergency setting because of its intrinsic diagnostic value. Management of acute aortic disease has changed with the increasing realization that endovascular therapies may offer distinct advantages in these situations. This article provides a summary of AAS, focusing especially on the multidetector CT (MDCT) technique, typical and atypical findings, and common pitfalls of AAS, as well as recent concepts regarding the subtypes of AAS, consisting of aortic dissection (AD), intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and unstable aortic aneurysm (UAA) or contained aortic rupture. MDCT findings will be related to pathophysiology, timing and management options to achieve a definite and timely diagnostic and therapeutic definition. In the present paper, we review the etiology, pathophysiology, clinical presentation, outcomes, and therapeutic approaches to acute aortic syndromes.