Reconstruction of the trapezius muscle using a pedicle latissimus dorsi flap was performed in a 27-year-old man with a large synovial sarcoma in his shoulder girdle. Size and location of the tumor required combined resection of surrounding muscles, including the trapezius, levator scapulae, and rhomboid major and minor. Thus, an extensive defect of the suspending muscles of the scapula was created after accomplishing an adequate resection of the tumor. The flap was performed to restore the trapezius functionally because there were no adjacent muscles available. The transferred muscle compensated for loss of the trapezius, thereby recovering excellent shoulder function. Although an opportunity of its application is thought to occur infrequently, the pedicle latissimus dorsi can activate scapular motion successfully in the absence of the levator scapulae. The technique may be extended to salvage failed conventional reconstruction after spinal accessory nerve palsy.