Esophageal duplication cysts are a rare medical entity. In most cases they are located at the level of the distal esophagus. Although our case is not unique, we want to focus on it as a reflection on diagnostic methods. The aim of this article is to show through the report on a case of esophageal duplication treated by us, followed by a review of similar cases in the literature, the utility of EUS in the diagnosis of upper-diaphragmatic and not communicating esophageal duplication. We report a case of a 43 year-old woman. She came to our attention for heartburn and retrosternal sense of space. The patient underwent an endoultrasonography (EUS) examination of the esophagus. The framework put EUS diagnosis of cystic formation of the esophagus (esophageal duplication cysts likely). We demonstrate that only EUS has a correlation with the determination of the pre-operative diagnosis with a statistical significance (p <0.001). In the diagnosis of esophageal not communicating duplication cysts EUS is the most specific diagnostic exam.