The patient was a 51-year-old male with a 3-year history of a slow-growing, asymptomatic, subcutaneous mass in the left temporal region. Magnetic resonance imaging revealed a well-defined extracranial lesion with heterogeneous enhancement and without invasion of the skull. A variety of soft tissue tumors were included in the differential diagnosis. The patient underwent total resection of the tumor, and a diagnosis of intramuscular myxoma was confirmed histologically. There was no evidence of recurrence at 6-month follow-up. The present case is the first characterization of the radiological appearance of intramuscular myxoma in the temporal muscle. I emphasize that increased awareness of this rare lesion and a careful clinical and radiological preoperative assessment are crucial in determining an appropriate treatment strategy for patients with a soft tissue tumor of the head.