Leiomyosarcoma of the head and neck is very rare, as only about 100 cases have been reported; of these, only 3 cases have been previously reported in the parapharyngeal space. We report the fourth such case, and we review the features of this entity. The patient was an 84-year-old woman who presented to the emergency department for treatment of an 18-month history of right-sided headache, a 6-month history of right-sided hearing loss and nasal obstruction, and a 2-month history of dysphagia. Physical examination revealed a bulge in the right side of the soft palate and the right lateral nasopharyngeal wall and complete obstruction of the right eustachian tube. Indirect laryngoscopy detected a bulge in the right lateral hypopharyngeal wall. Otoscopy revealed otitis media with effusion in the right ear. Imaging demonstrated a space-occupying lesion in the right parapharyngeal space that extended from the base of the skull to the level of the hypopharynx. Biopsy and histology identified the mass as a leiomyosarcoma. Metastasis to the brain was discovered shortly thereafter, and the patient died 10 months later. The unusual presentation of head and neck leiomyosarcoma requires a high index of suspicion and appropriate diagnostic imaging. Surgical excision is the recommended treatment when feasible; chemoradiotherapy does not appear to affect disease progression.