Liposarcoma is one of the most prevalent soft tissue sarcomas, accounting for about15%-20 % of all mesenchymal malignancies. The most common sites are the limbs, retroperitoneum, and visceral sit. Herein, we reported a case of a liposarcoma in a male patient’s stomach. The patient was a 76-year-old man, who presented with symptoms of atypical dyspepsia and enlargement of abdomen from one year before this investigation. CT revealed a large thin-walled cyst, measuring 230 × 210 × 160 mm without solid part, containing a few thin vascular septations; it was seen in upper abdomen in the midline in front of the pancreas and stomach. The mass was resected with the sleeve gastrectomy of lesser curvature. The histopathological examination was in favor of sarcoma and the IHC consistent with well-differentiated liposarcoma. The patient did not receive any adjuvant treatments and he is under close follow-up.