We report a rare case of myxofibrosarcoma arising in the neck. A 55-year-old man presented with a two-year history of left-sided, painless, submandibular swelling. Computed tomography and magnetic resonance imaging (MRI) revealed an 80 × 35 mm, well defined, lobulated, submandibular tumour extending to the parapharyngeal space. The tumour showed uniformly low intensity and marked hyperintensity in T1- and T2-weighted MRI scans, respectively, and was scarcely enhanced by gadolinium. A tentative diagnosis of lymphangioma or plunging ranula was made, and the patient underwent local injection of OK-432, which proved to be ineffective. Resection of the tumour was then performed via a transcervical approach. The tumour was histopathologically and immunohistochemically diagnosed as a low-grade myxofibrosarcoma. The patient's post-operative clinical course was uneventful, and the patient was free of disease 27 months after surgery. The pathology, clinical characteristics and treatment of myxofibrosarcoma are bibliographically reviewed.