Frey syndrome is a disease characterized by abnormal sweating, facial redness, and rare pain by stimulation of taste sense on the limited area dominated by the auriculotemporal nerve and great auricular nerve. Although the developmental mechanism and histopathologic cause of Frey syndrome are still being debated, the most reliable theory is based on injury of the parathympathetic nerve connected to the auriculotemporal nerve continuing to abnormal regeneration. The other theory is that the sweat glands develop an increased sensitivity after degeneration of sympathetic fibers. Therapy of Frey syndrome includes drugs, radiographic treatment, and surgical treatment; however, in most cases, treatment is not satisfactory. This is a case report on a 24-year-old male patient with Frey syndrome caused by the fracture reduction with retromandibular approach after multiple facial traumas and spontaneous healing without any special treatment.