A previously healthy 56-year-old female was hospitalized with intermittent melena and transient syncope for 1-month duration. Physical examination on admission showed heart rate was 105 beats per minute and blood pressure was 89/55 mmHg. Her hemoglobin was 6.7 g/dl. She received fluid infusion, blood transfusion, acid suppression and hemostasis treatment. Abdominal enhanced computed tomography (CT) demonstrated a well-defined mass with uniform adipose density in the antrum measuring 4 × 5 cm. Gastroscopy revealed a giant submucosal tumor with superficial ulceration in anterior wall of the gastric antrum. Endoscopic ultrasound (EUS) showed a homogeneous, well-circumscribed, hyperechoic mass originated from the submucosa layer. Distal partial gastrectomy was performed. Postoperative histopathology examination of the resected specimen revealed the tumor was composed of closely arranged and uniformly shaped proliferative mature adipocytes, which located in the submucosa layer with superficial mucosal ulcer. The patient was diagnosed as giant gastric lipoma with superficial ulcer and no symptoms was observed in 3 months follow-up.