Lesions of the retropharyngeal space (RPS) are uncommon, and they generally present as solitary, painless masses, which are often cystic. They usually originate from branchial arches anomalies, and only in a few cases do they turn out to be bronchogenic cysts. Generally, these lesions are diagnosed in childhood, but sometimes they can appear in adulthood. We report here a rare case of a bronchogenic cyst expanding into the RPS and causing dysphagia in an adult patient treated surgically. Since the RPS is clinically inaccessible, clinical examination was not crucial in determining the correct diagnosis, and only the additional information provided by radiological examinations led to the final diagnosis, which is essential for accurate surgical planning.