Thoracic outlet syndrome (TOS) is a group of disorders characterized by compression of nerves, arteries or veins (or all three structures simultaneously) at the level of the upper chest opening. The exact incidence of thoracic outlet syndrome is unknown and most cases are diagnosed between the ages of 20 and 50; estimates range from 3 to 80 cases per 1000 population. TOS can be classified as neurogenic, arterial, or venous based on the compressed structure. In the vast majority of cases, neurogenic TOS occurs (more than 95% of cases). Although venous TOS (between 3% and 4%) and arterial TOS (between 1% and 2% of cases) are significantly less common, their consequences are usually more serious and often require urgent treatment. Based on a potential lack of correspondence between neurophysiological testing and clinical examination outcomes, the diagnosis and management of TOS has remained open to discussion. The diagnosis of TOS can be made through history, physical examination maneuvers, and imaging. Vascular lesions and clinical symptoms associated with thoracic outlet compression are typically easily recognized, such as effort thrombosis of the subclavian vein or poststenotic aneurysm of the subclavian artery. Nonsurgical treatment includes anti-inflammatory drugs, weight loss, and physical therapy/strengthening exercises. The most common surgical treatments include brachial plexus decompression, and scalotomy with or without first rib resection. Surgery is generally proposed for vascular or neurogenic TOS that does not respond to a conservative treatment. Arterial TOS requires a surgical treatment in most cases.