The treatment of advanced cancer of the maxillary sinus often requires extensive ablation and orbital exenteration that results in large full-thickness defects of the upper cheek and orbital regions. Reconstruction of such defects with local flaps is usually difficult because of the need for a large flap. Several regional flaps such as the deltopectoral flap, the temporal flap, and the shoulder flap may be used, but these techniques frequently require surgery in stages and result in severe deformity of the donor site. The island pedicled, pectoralis major myocutaneous flap may be rotated up to the orbital region; however, the uncertain blood supply to the skin in the distal area of the pectoralis may cause unexpected marginal necrosis of the flap. Reconstruction of large orbital-maxillary defects can readily be accomplished in one stage using microsurgical free transfer of latissimus dorsi myocutaneous flaps. The thoracodorsal artery and vein that form the nutrient pedicle of the flap approaches 2 mm in external diameter and up to 10 cm in length, allowing greater versatility in head and neck reconstruction. The muscle may be used to fill the orbital and maxillary cavities and will accept a skin graft on its deep surface. The donor defect is closed primarily and the resulting scar is well concealed beneath the arm. If necessary, extremely large flaps may be transferred by harvesting the entire latissimus dorsi muscle and the overlying skin based on the thoracodorsal system.