Numerous mycoutaneous island flaps or free flaps have been used to reconstruct a defect which resulted from the wide resection of tumor mass in head and neck region. Since the curative resection of tumor usually include muscles and bones as well as skin and mucosa, the anatomical and functional restoration of the defect depend on which and what amount of tissues were provided to cover the defect; good aesthetic appearance subsequently follows the result. Furthermore, a simultaneous neck nodes dissection usually results in exposure of major neck vessels., which should be protected with sufficient padding. The ideal method to reconstruct a defect in the head and neck region requires a sufficient coverage by muscle layer with good vascularity, a wide arc of rotation, and minimization of donor site defect. The pectoralis major myocutaneous flap which was first decribed by Ariyan and lateral trapezius myocutaneous flap by Demergasso meet these criteria. We describe the use of these myocutaneous flaps in reconstruction of mandible and oral cavity.