Gastric carcinosarcoma is a rare cancer of adults with poor prognosis compared with other gastric malignancies. To the best of our knowledge, the present report is the first case of gastric carcinosarcoma with chondroblastic differentiation in Iran. A 63-year-old man with epigastric pain was admitted to the surgery department. Abdominopelvic CT-scan showed a hypodense mass lesion in distal gastric lesser curvature measuring 5.7 x 4.0 cm with decreased enhancement after contrast injection. Microscopic examination revealed coexistence of carcinomatous and sarcomatous components, presence of vascular and perineural invasion and involvement of the adjacent lymph nodes. This is a report of a rare case of gastric carcinosarcoma with chondroblastic differentiation.