Through the Vietnam Vascular Registry which was established in 1966 at Walter Reed Army Medical Center, copies of medical records of 509 combat casualties with 558 arteriovenous fistulas and false aneurysms have been analyzed. This represents approximately 7 percent of the vascular injuries in American casualties from Southeast Asia, from 1963 to 1972, which are included in the Registry effort. Contributions of several hundred individuals are included in this documentation, however, more than one fourth of the patients, 149 or 29.3 percent, have been evaluated in our clinic. There were 296 false aneurysms and 262 arteriovenous fistulas. Multiple lesions occurred in 7.9 percent of the casualties. Fragment wounds accounted for 487 or 87.3 percent of the lesions with 85.5 percent in extremity vessels. Early recognition and definitive surgical treatment usually were accomplished: 52.8 percent within the first 30 days following injury. Ligation was either accepted or required in about 50 percent of the lesions. The mortality rate was 1.8 percent and the morbidity associated with the vascular injury was 6.3 percent. There were eight amputations for an amputation rate of 1.7 percent. Potential complications of heart failure, proximal arterial dilatation, and endocarditis were essentially absent.