Gastric foregut duplication cyst is a rare congenital disease. It is usually revealed with imaging study during the diagnosis of nonspecific symptoms, such as abdominal pain, nausea, and vomiting. Here we report the case of a male patient who underwent imaging study for the examination of a benign prostatic hyperplasia. A 3-cm mass containing cystic areas behind the gastric fundus was revealed on abdominal computed tomography. Laparoscopic gastric wedge resection was performed and the histopathological work-up of the specimen was reported as a foregut duplication cyst.