Thoracic aortic aneurysm (TAA) is the most common pathology of the thoracic aorta. The incidence of TAA is increasing and the true incidence of TAA is likely to be higher than currently reported because of its inherently silent nature. TAAs are an increasingly recognized condition that is diagnosed incidentally on imaging studies performed to evaluate unrelated conditions because most patients with TAA have no symptoms. TAAs normally grow in an indolent manner, but can become rapidly lethal once dissection or rupture occurs. Indeed, aortic aneurysms (both abdominal and thoracic) represent the 15th leading cause of death in individuals older than 55 years, and the 19th leading cause of death in individuals of all ages in the United States. The etiologies underlying TAAs are diverse. Therefore, the evaluation and management of TAAs are complex. The present review summarizes the knowledge of the pathophysiology, natural history and diagnostic modalities, as well as current treatment strategies of TAA on the basis of current literature.