The term acute aortic syndrome (AAS), coined several years ago, is now widely recognised. In the light of new findings in aortic pathology and in an era when modern imaging techniques are widely available and interventional management of AAS is increasing, some morphological and diagnostic aspects of acute aortic pathology have been examined and the syndrome updated. This article provides a new, comprehensive overview of the pathology, diagnosis, evolution and management of patients with AAS. As acute aortic disease is the most common fatal condition in patients with chest pain, prompt recognition and treatment is of paramount importance.