The incidence of upper extremity venous thrombosis has been steadily increasing since the 1960s. In patients presenting with swelling, pain, tenderness, palpable cord in the upper extremity, or history of central line placement, duplex ultrasound may be the best approach for making the initial diagnosis of upper extremity venous thrombosis. This program explores duplex examination of the upper extremity veins, as prescribed by the Professional Performance Guidelines of the Society for Vascular Ultrasound (SVU).