Posttraumatic pulmonary arteriovenous fistula is a rare complication of penetrating injury. Cases may remain asymptomatic for years prior to diagnosis. We present a case of pulmonary arteriovenous fistula related to a penetrating injury of the thorax 6 years previously that was occluded with a septal occluder device. Consistent use of CT or conventional catheter pulmonary angiography following penetrating injury to the thorax is essential to the early diagnosis of pulmonary arteriovenous fistula during the asymptomatic stage. Modern occlude devices facilitate the transcatheter approach as a viable alternative to surgery for the closure large, high pressure defects.