Although microsurgical transplantation of the sternocostal segment of the pectoralis major muscle shares most of the advantages of the latissimus dorsi free flap, the latter has become a workhorse of microsurgery and the segmental pectoralis major free flap has not. By presenting their clinical experience with primary transplantations of this free flap to reconstruct craniofacial defects, the authors intend to draw more attention to its application and promote its use in reconstructive surgery. Segmental pectoralis major free flaps were used for reconstruction of craniofacial defects in four male oncologic patients and one female trauma patient with a mean age of 55 years (range, 37 to 68 years). The donor-site morbidity was limited by preserving the clavicular muscle segment and its innervation. In one patient, only part of the sternocostal segment of the muscle was harvested, whereas in another, the free flap's vascular pedicle was anastomosed to the vascular pedicle of the contralateral pedicled pectoralis major flap. Total flap loss occurred in the one trauma patient and repeated surgery for wound-healing problems was required in one of the oncologic patients. Still, final flap outcome was favorable in four of the five patients. The segmental pectoralis major free flap is a useful and justifiable adjunct to the microsurgical techniques available for flat or wide craniofacial defects. It has the advantage over the latissimus dorsi flap of allowing a simultaneous two-team approach with the patient in supine position.