Gastric duplication cysts (GDCs) are rare congenital anomalies that primarily occur in childhood but can also manifest in adults. While the ileum is the most common site of duplication, gastric duplications are infrequent. Symptomatic GDCs typically present with upper abdominal pain, vomiting, and occasionally as palpable abdominal masses. Diagnostic imaging, particularly cross-sectional techniques, plays a crucial role in identifying these cysts, and surgical resection is the definitive curative treatment.We report the case of a 44-year-old female who presented with severe right-side upper abdominal pain accompanied by non-bilious vomiting. Initial basic blood investigations yielded normal results. Subsequent contrast-enhanced computed tomography revealed a non-enhancing cystic lesion of size 9x8.5x6.5cm in the left suprarenal region lying posterior to the stomach suggestive of either a GDC or an adrenal cyst. Another hyperdense peripherally enhancing lesion was observed in the right adrenal gland, indicating a right adrenal cyst with internal hemorrhage. During laparotomy, the left side cystic lesion was found arising from the posterior wall of the greater curvature of the stomach, along with another cystic lesion of about 3x3cm originating from the right adrenal gland. Both cystic lesions were successfully excised, and the patient experienced a smooth postoperative recovery without any complications. Histopathological examination confirmed the presence of a cyst lined by gastric-type epithelium with underlying smooth muscle fibers consistent with GDCs. The right adrenal gland cystic lesion exhibited central areas of hemorrhage and necrosis.