BACKGROUND The extent of tissue loss amenable to primary healing after revascularization is unknown. Salvage of limbs with large soft-tissue defects with exposed tendon, joint, or bone lies beyond the limits of conventional techniques. We report our results using free tissue transfer as an adjunct to lower extremity vascular reconstruction in patients with complex ischemic or infected wounds. METHODS Retrospective chart review of patient and wound characteristics. RESULTS From January 1992 to June 1996, 585 procedures were performed in 544 patients, including 27 free flaps in 26 patients: 17 free flaps combined with distal bypass (7 staged, 10 simultaneous) and 10 isolated free flaps. Flap donor sites included radial forearm (8), latissimus dorsi (7), rectus abdominus (9), and scapula (3). Surgical indications included extensive ischemic/neurotrophic ulcers, and nonhealing vein graft harvest incision or transmetatarsal amputation site. Mean area of tissue loss was 70 cm2, mean ulcer duration was 5 months, and 92% of patients had exposed tendon, joint, or bone. During a mean follow-up of 14 months, 2 patients died of cardiopulmonary disease and 3 flaps failed, resulting in below-knee amputation. Six flaps were revised for graft stenosis (1), venous thrombosis (1), or flap edge necrosis (4). Limb salvage rate was 70% at 24 months by life-table analysis. Functional ambulation was achieved in 21 of 24 (88%) patients, including 7 of 8 with diabetes, end-stage renal disease, and heel ulcers. CONCLUSIONS In select ambulatory patients with large soft-tissue defects and exposed deep structures, functional limb salvage is obtainable in more than 80% of patients. For lesions not amenable to vascular reconstruction with conventional methods of wound coverage, free tissue transfer extends the limits of limb salvage and is a viable alternative to amputation.