Acute thoracic aortic dissection is part of the acute aortic syndrome triad.Caused by an intimal tear in the lumen of the aorta,it leads to the creation and propagation of a false lumen.In the acute setting this can lead to malignant hypertension,pain and end organ malperfusion.In the chronic setting it can lead to aneurysm formation and rupture.It remains the most common aortic emergency,affecting up to 4 per 100000 people per year in the United Kingdom and United States.Despite advances in treatment and centralisation of vascular services,it continues to be associated with a high pre-admission and in-hospital mortality.Dissection is classified in several ways according to anatomical extent,timing and underlying pathology,all of which guides clinical management.Traditionally,medical management has been the mainstay of treatment in patients with uncomplicated disease.Surgery has been used in symptomatic patients.With published information now available from several prospective international registries,we are beginning to see the advantages of newer surgical treatment options such as endovascular repair,in the acute setting.This review provides an update on diagnosis and management of aortic dissection,including new information that has become available in recent years.