Traumatic obstruction of the subclavian artery without major hemorrhage is rare. Only eleven cases have been disclosed retrograde flows from the ipsilateral vertebral artery into the distal segment of subclavian artery in the world. One case of the traumatic subclavian occlusion is presented in this paper. A 63-year-old man was struck on his chest by heavy machinery. On admission he was alert and had no neurological deficits. His blood pressure was 140/80 mmHg in his right arm but was not palpable in his left radial artery. Aortogram showed incomplete obstruction of the left subclavian artery 2 cm beyond its origin. On the second admission day it was occluded and the distal flow was supplied from the left vertebral artery in a retrograde fashion. Without operative vascular reconstruction he has never experienced ischemic symptoms for a year.