Various methods of laryngeal reconstruction such as skin graft, skin flap, myocutaneous flap, hypopharyngeal mucosal flap, pedicled muscle flap, and composite autologous cartilage graft have been developed since the early 1950s, but they have their own advantages and disadvantages. The goals of reconstruction for laryngeal defects are obviously to provide a suitable airway and a normal voice. In order to accomplish this, it is necessary to provide a permanent supportive framework over which the mucosa can regenerate. Preservation of the laryngeal musculature and recurrent laryngeal nerve is also essential. Authors performed reconstruction with sternocleidomastoid myoperiosteal flap over the laryngeal defect after hemilaryngectomy in mongrel dog and evaluated postoperative courses, laryngeal functions and histologic features. This study demonstrated the ability of the sternocleidomastoid myoperiosteal flap not only to survive but to develop into squamous and respiratory mucosal epithelization. The sternocleidomastoid myoperiosteal flap is ideal because of its pliable nature, which allows it to conform to any laryngeal defect and permits airtight closure.