Lateral composite mandibular defects resulting from excision of advanced oral carcinoma often require mandible, intra-oral lining, external face, and soft-tissue bulk reconstruction. Ignorance of importance soft-tissue deficit in those patients may cause significant morbidity and functional loss. Such defects, therefore, can be reconstructed best with a double free flap technique. However, this procedure may not be feasible for every patient or surgeon. An alternative procedure is a free fibula osteoseptocutaneous flap combined with a pedicled pectoralis major myocutaneous flap. This combination was used in reconstruction of extensive composite mandibular defects in 14 patients with T3/T4 oral squamous cell carcinoma. All patients were men, and the average age was 54.3 years. The septocutaneous paddle of the fibula flap was used for the mucosal lining of the defects while the bony part established the rigid mandibular continuity. The pectoralis major flap then covered the external skin defect in the face and cheek, and the dead spaces left by the extirpated masticator muscles, buccal fat, and parotid gland. One free fibula flap failed totally, and one pectoralis major flap developed marginal necrosis. At the time of final evaluation, nine patients (64.3 percent) were alive, surviving an average of 25.7 months. All patients eventually regained their oral continence and an acceptable cosmetic appearance. In conclusion, the fibula osteoseptocutaneous flap plus regional myocutaneous flap choice is a successful and technically less demanding alternative to the double free flap procedures in reconstruction of extensive lateral mandibular defects.