Deep venous thrombosis (DVT) is common, but only 2%-4% of DVTs involve the upper extremities (Roos in Am J Surg 154:568-73, 1987). Upper extremity DVT has a primary or secondary cause, and primary thrombosis is much rarer than secondary thrombosis. Primary upper extremity DVT comprises effort venous thrombosis and idiopathic thrombosis. Effort subclavian venous thrombosis, also called Paget-Schroetter syndrome, is an uncommon entity, which usually develops after strenuous effort of the upper extremities. Effort thrombosis of the upper extremity has been described in athletes involved in a wide variety of sports, including ball games, combatant sport and heavy athletics, games with rackets or clubs, and aquatic sports (Zell et al. in Angiology 52:337-42, 2001). Push-up exercise is a strengthening exercise for building up strength and endurance in the muscles of the upper arm and shoulders. It is also considered to be a core exercise in shoulder rehabilitation programs to activate the serratus anterior muscle in people with shoulder dysfunction (Ludewig et al. in J Sports Med 32:484-93, 2004). We report what to our knowledge is the first case of effort DVT of an upper extremity caused by push-up exercise.