In severe traumatic injuries to the lower extremity, it is often a difficult decision to attempt heroic efforts aimed at limb salvage or to amputate primarily. To answer this question, the authors performed a 5-year review of 70 limbs in 67 patients. Patients were identified as presenting with major lower extremity trauma and an associated arterial injury. Nineteen (27%) of the 70 limbs were amputated. Limb salvage was not related to the presence or absence of shock and order of repair (orthopedic or vascular). No statistical difference was noted between the time of injury to operative repair in either the amputated or limb salvage group. Limb salvage was related to warm ischemia time and the quantitative degree of arterial, nerve, bone, muscle, skin, and venous injury. A limb salvage index (LSI) was formulated based on the degree of injury to these systems. All 51 patients with an LSI score of less than 6 had successful limb salvage (p less than 0.001). All 19 patients with an LSI score of 6 or greater had amputations (p less than 0.001). Although statistics cannot replace clinical judgment, this index can be a valuable objective tool in the evaluation of the patient with a severely traumatized extremity.