Thromboembolic complications are very rare after arthroscopic surgery of the shoulder. We report the case of a 25-year-old who presented thrombophlebitis of the brachial vein complicated by pulmonary embolism following arthroscopic surgery for posterior instability of the shoulder. No hemostasis impairment was found in this patient. The factors arguing in favor of thrombosis that had been retained from the literature were the lateral decubitus position with traction of the limb in its axis, prolonged surgical time, use of interscalene brachial plexus block, and a general condition susceptible to thrombosis (personal or family history of thromboembolism, genetic risk factor for thrombosis, smoking, obesity, neoplasia). There are currently no guidelines on the need for thromboembolism prevention during shoulder arthroscopy.