Introduction <p>Gastric duplication cysts (GDCs) are uncommon congenital anomalies of the gastrointestinal system, accounting for about 2–9% of all the duplications in the gastrointestinal tract. GDCs are commonly diagnosed in childhood, typically remain asymptomatic in adults, and are discovered incidentally. GDCs are characterized by their cystic nature, lined by gastrointestinal epithelium and surrounded by smooth muscle that integrates with the gastric wall. The greater curvature of the stomach is the common location, and their cystic appearance makes them indistinguishable from other cystic abdominal pathologies radiologically.</p> Case Presentation <p>A 39-year-old male presented to the department of General Surgery with complaints of abdominal pain, distension, discomfort, and vomiting. He gave history of similar episodes in the past, leading to a diagnosis of pancreatitis and subsequent medications. Notably, the patient had a 20-year history of alcohol consumption, which was linked to his prior episodes. Radiological findings revealed a well-defined, encapsulated cystic lesion along the greater curvature of the stomach. The patient underwent surgery, and the sleeve gastrectomy specimen including the attached cystic mass was sent for histopathological examination (HPE) when the diagnosis was established as gastric duplication cyst.</p> Conclusion <p>Gastric duplication cysts are a rare entity, with a wide spectrum of manifestations, which might be misdiagnosed easily as various other diseases. These should be considered in the list of differentials when evaluating submucosal gastric masses, and a thorough investigation is of utmost importance to accurately establish the diagnosis of GDCs, as it allows adequate treatment and avoids unnecessary interventions.</p>