An 18-year-old man sustained a clavicular open fracture and a 1.5 cm long subclavian artery laceration because of a penetrating injury received in a traffic accident. This type of trauma is rare. Physical examination at the emergency room showed shock, supraclavicular hematoma, foreign body retention and diminished ipsilateral radial and ulnar pulsation at the wrist level. Emergent debridement, removal of the metal foreign body (a broken mirror-bar from the patient's motorcycle), repair of the subclavian artery and internal fixation of the clavicle with a Knowles pin were performed after resuscitation with 1000 mL of ringer solution and four units of blood packed cells. The patient completely recovered his shoulder functions three months later. This case highlights the importance of ruling out associated major arterial injury in patients with a penetrating injury near the thoracic outlet and neck with unstable vital signs.