Ectopic pancreas (EP) is defined as pancreatic tissue that lacks anatomical or vascular connections to the normal pancreas. EP is generally asymptomatic and is detected incidentally during endoscopy. However, due to pseudocyst formation, inflammation, or malignant transformation, it may cause non-specific gastrointestinal symptoms, such as abdominal pain, abdominal discomfort, nausea, vomiting, and bleeding. Pseudocyst formation in EP may result from the retention of exocrine secretions in the absence of connections between the glandular epithelium and gastric lumen. We herein report a case of EP with a pseudocyst associated with epigastric pain. EP with a pseudocyst, although rare, needs to be considered in a differential diagnosis of cystic lesions of the stomach.