Autologous bone grafts harvested from the iliac crest are commonly used in reconstructive orthopaedic surgery. Autologous bone is used to help promote bone healing in fractures and to provide structural support for reconstructive surgery. The results of autologous bone grafting are more predictable than the use of xenografts, cadaveric allografts, or synthetic bone substitutes because autologous bone grafts provide osteoinductive and osteoconductive properties, are not immunogenic, and are usually well incorporated into the graft site. In a retrospective review of 414 consecutive cases of iliac crest bone graft procedures performed at Brooke Army Medical Center from 1983 to 1993, 41 (10%) minor and 24 (5.8%) major complications were identified. Minor complications included superficial infections, superficial seromas, and minor hematomas. Major complications included herniation of abdominal contents through massive bone graft donor sites, vascular injuries, deep infections at the donor site, neurologic injuries, deep hematoma formation requiring surgical intervention, and iliac wing fractures. Harvesting of iliac crest bone graft can be associated with significant morbidity. However, with adequate preoperative planning and proper surgical technique, the incidence of these complications can be reduced.