The need to relieve muscle swelling and secondary vascular impairment of an extremity may occur following a variety of conditions. Regardless of the type of insult, massive swelling of an extremity can result in ischemic necrosis of muscle as a result of tamponade produced by restrictive circulferential fascia. When intracompartmental pressure approaches or exceeds arterial pressure, a portion or the entire extremity may be in jeopardy. Fasciotomy is one of the most important adjunctive procedures available to assure survival of an extremity with altered distal circulation resulting from massive swelling. Its importance has been stressed infrequently in the literature. The indications for its use are outlined in a variety of clinical situations. The proper techniques have few complications and much to offer with regard to limb salvage and reduction of morbidity. Fasciotomy does not preclude correction of the underlying cause for restrictive muscle tamponade when possible, nor can it be expected to reverse well established ischemia. Early and liberal use of fasciotomy is advocated when the outlined indications prevail.