The intimal flap may occur in any artery after severe blunt trauma with or without fracture of bone and occasionally in high-velocity gunshot wounds. It should be suspected in any patient with a history of blunt trauma who has signs of arterial insufficiency. On arteriography, it is recognized by a bandlike shadow in the column of dye and diminution in the density of dye distal to the band, although complete occlusion may be seen also. The lesion requires prompt surgical correction by either resection of the artery or intimectomy with or without a vein patch. The 49 cases reported in the literature have been summarized, and we have added reports of nine new cases.