Improved techniques and experience in microvascular surgery make it possible to repair vessels and replant digits and extremities with increasing success. Patients with sharp or localized crush injuries are excellent candidates, and the expected survival of the extremities is greater than 80%. A good functional result can be anticipated. Generalized crush and avulsion injuries, which were common in our clinical experience, are difficult problems requiring careful selection criteria, appreciation of diffuse vessel damage that may require bypass vein or artery grafts, and the appropriate use of anticoagulants to prevent vessel thrombosis. Severe crush or mangled hand injuries, brachial plexus nerve avulsions, multilevel crush or power takeoff injuries, and excessive bacterial wound contamination are unfavorable situations for revascularization efforts, and the expected results are poor. To warrant attempts at revascularization, it must be anticipated that nerve regeneration and muscle function will be achieved and that functional use will be better than that possible with a prosthesis.