Between 1978 and 1988, 50 patients were demonstrated arteriographically to have 61 nonocclusive arterial injuries (44 major arteries, 17 minor arteries). The 61 injuries consisted of 19 intimal defects, 4 intimal flaps, 26 pseudoaneurysms, 2 arterial stenoses, and 10 arteriovenous fistulas. End-organ ischemia or ongoing hemorrhage were not present. All patients were treated nonoperatively. At 1 to 12 weeks after the injury, 30 arterial injuries (24 major, 6 minor) were studied by repeated arteriography. Resolution, improvement, or stabilization of the injury occurred in 21 (87%) major artery injuries. Progression occurred in the remaining 3 injuries, including 1 patient who underwent subsequent successful repair. Twenty-one injuries were followed up without repeated arteriography. Delayed arterial thrombosis, hemorrhage, or ischemia did not develop, and no patient required operative management. Eight of 10 additional arterial injuries had successful percutaneous embolization at the time of repeated arteriography. The overwhelming majority of small arterial injuries or intimal fractures do not lead to vascular complications if managed nonoperatively. A routine policy of operative exploration for all such injuries is therefore unwarranted. These injuries are best managed by observation and serial arteriography to document spontaneous healing or progression.