Background: Esophageal duplication cysts are rare congenital tumors usually diagnosed and treated during childhood. Most of them are located in the mediastinum and appear as a mass besides the esophagus. Unfortunately, symptoms are non-specific and depend on the size and location of the mass; therefore, they can easily be missed. If symptoms appear, surgical resection is necessary to prevent troublesome complications. Case Presentation: We present the case of a 60-year-old woman who presented with severe progressive dysphagia and epigastric pain. After further evaluation, a paraesophageal cystic mass was found, and surgery was required. Non-communicating esophageal duplication cyst was the final diagnosis. Conclusion: Esophageal duplication cysts are a rare pathology in adults; their symptoms will vary depending on their size and location. Preoperative diagnosis is difficult as symptoms are non-specific and can be missed. If severe dysphagia, pain, or any other complication appears, surgery should not be delayed.