Our objective was to evaluate whether physical examination in conjunction with chest X-ray can accurately diagnose the presence of significant vascular injury in penetrating periclavicular trauma. Results from a management protocol for penetrating periclavicular trauma were reviewed for the period January 1992 through December 1996 at an urban Level I trauma center. All patients requiring angiography for periclavicular penetrating trauma with trajectory of the injury falling between the lateral border of the manubrium and the anterior axillary line were entered into the management protocol. All patients underwent anterior-posterior chest radiography on arrival to the trauma center and 6 hours after admission. Tube thoracostomy was placed if clinically indicated on presentation or for X-ray findings. Clinical assessment was performed on all patients, with emphasis placed on the presence of "hard" signs for vascular injury. In addition to accepted hard signs for vascular injury, significant chest tube output (>1000 cc) and chest X-ray findings consistent with significant hemorrhage were also considered hard signs for vascular injury. Assuming hemodynamic stability, all patients with suspected subclavian/axillary arterial injury based on wound trajectory or clinical findings consistent with vascular injury underwent angiography. Forty-six patients were entered into the protocol with 30 left-sided injuries and 16 right sided injuries. The majority of injuries were secondary to gunshot wounds (31), with 14 stab wounds and 1 shotgun injury. Emergency room chest X-ray results revealed 32 negative chest X-rays, 7 pneumothoraces, 2 hemopneumothoraces, 2 hemothoraces, and 3 chest tubes placed before initial chest X-ray. A total of 7 injuries were diagnosed, with 1 missed injury, resulting in a sensitivity of 86 per cent for clinical assessment. The missed injury was a pseudoaneurysm of an axillary artery secondary to a self-inflicted shotgun wound. One mortality occurred in this series, which was a death in the operating room secondary to blood loss from an axillary artery injury. We conclude that clinical assessment can adequately diagnose the presence of surgically significant vascular injury in periclavicular penetrating injuries with trajectories lateral to the manubrium.