Lymphangioma is presented as a painless mass with a soft consistency in the head and neck. The involvement of retropharyngeal space in lymphangioma is rare. Here, we presented the case of retropharyngeal lymphangioma and discussed its manifestations, imaging, and treatment. An 11-year-old female was presented with shortness of breath, stridor, fever, dysphagia and drooling. Clinical examinations revealed a retropharyngeal swelling and a hot-potato speech. MRI revealed the multicystic lesions extending from the base of the skull to the level of T4 in retropharyngeal space. The mass resection was done under general anesthesia and 5 ml dehydrated alcohol was injected as sclerotherapy. The pathological analysis yielded cystic hygroma. The six months post-surgery follow up showed no recurrence, and the patient remained symptoms free. Retropharyngeal lymphangioma should be considered as a differential diagnosis of retropharyngeal abscess. Their treatment in primary and acute conditions is the same, including drainage, intravenous antibiotics therapy, and airway care. However, diagnosis of retropharyngeal lymphangioma is important because it needs farther evaluation and treatment. Few cases of retropharyngeal lymphangioma were reported, and this was a challenging case with a wide area of involvement.