Nontraumatic haematoma of parapharyngeal space is very rare and may cause dysphagia and dyspnea. The authors present a case report of a 74-year-old woman with sudden nontraumatic neck swelling without dyspnea and with left pharyngeal bulging and endolaryngeal displacement. Parathyroid hormone elevation and imaging exams confirmed bleeding from a parathyroid adenoma. Symptoms and signs resolved after one week of conservative treatment. There are few cases of parapharyngeal haematomas caused by parathyroid adenomas. Most patients can be managed without emergent surgery, but close airway monitoring is fundamental.