Many surgeons have demonstrated the validity of sternocleidomastoid muscle flaps for the reconstruction of head and neck tumors. We present a case in which we used an island sternocleidomastoid muscle flap to reconstruct a cheek depression after excision of a malignant parotid tumor. A 44-year-old woman presented with a right malignant parotid tumor. We performed total resection of the parotid gland and facial nerve with the sural nerve and reconstructed the facial nerve and cheek depression with an island sternocleidomastoid muscle flap. The sternal head of the right sternocleidomastoid muscle was cut at the cranial and caudal segments to elevate it as an island flap. We used the superior thyroid artery as the sole pedicle for the island muscle flap. At 1 year and 3 months after the operation, the mimic muscles had gradually recovered and progressed without complications such as Frey syndrome, cervical motor dysfunction, or concave deformation of the neck and cheeks.