To determine indications for immediate or delayed amputation of the mangled lower extremity, we reviewed the cases of 80 patients. Vascular, neurologic, bone, and soft-tissue status were reviewed, as were postoperative complications, requirements for mechanical ventilation, fluid balance, delayed amputation, and survival. Although neurologic, bone, and soft-tissue status did influence decisions regarding immediate amputation, they had little to do with delayed loss of limb or life. The circulation, as determined by the presence or absence of a palpable or Doppler-detected pulse, however, was critical. Of six patients in whom salvage was attempted and in whom fluid balances of greater than 3 L were detected in the first 24 hours post-operatively, five eventually required amputation. Salvage should usually be attempted if a distal pulse is present. If no distal pulse is present, the decision for immediate amputation should be based on functional prognosis. In cases in which salvage is attempted, amputation should be performed at 24 hours if the patient's condition, including a markedly positive fluid balance, indicates systemic compromise. In the absence of a distal pulse on presentation, the eventual amputation rate is high.