In the treatment of jaw bone atrophies, autologus bone is still considered the gold standard because of its excellent osteoconductive, osteoinductive, and osteogenetic proprieties and lack of immunogenicity, which allow better graft integration and stability. Although various donor sites are available, the iliac crest represents the best source of corticocancellous bone, and literature suggests that it has low morbidity. However, this case report emphasizes that patients with systemic diseases such as anorexia should be carefully evaluated before such an operation, because unfavorable bone conditions may jeopardize the outcome. A 47-year-old woman needing rehabilitation of the upper arch was considered for iliac crest harvesting. She stated that she had suffered from anorexia for 30 years. A corticocancellous block was harvested by a bone saw using an anterolateral approach to the outer table of the right anterior iliac crest. The postoperative course was uneventful, but 13 days later, she complained of a sudden pain in the operated area, and X rays revealed a fracture of the anterior iliac crest. So far, the literature has mentioned 50 cases of iliac crest fractures after bone harvesting, and 28 cases among these are due to harvesting in the anterior part of the iliac crest. Several factors seem to be responsible for this complication, including the area of harvesting, residual bone thickness, technique used, and age and gender of the patient. To our knowledge, our case is the first of hip fracture after bone harvesting in a patient suffering from anorexia. Both low weight and osteoporosis are probably responsible for this complication. In our opinion, patients suffering from anorexia should be considered at risk for bone harvesting, and an appropriate mini-invasive surgical technique should be carried out instead.