We report a case of transverse colon cancer with gastric regional lymph node metastasis. A 50-year-old man was admitted to our hospital for abdominal distension and abnormal evacuation. He was diagnosed with advanced transverse colon cancer with regional lymph node metastasis by a barium enema examination and computed tomography. In operative findings, the main tumor at splenic flexure had invaded greater omentum. Therefore, left hemicolectomy with D3 lymph node dissection including gastroepiploic lymph node (classified to No. 204) was performed. Histopathological examination revealed the metastasis to gastroepiploic lymph node. Six months after initial surgery, mediastinal and hilar lymph node swelling was detected by follow-up CT scan, although mFOLFOX6 was administered as postoperative adjuvant chemotherapy. We therefore performed FOLFIRI as second-line chemotherapy. He had a stable disease during FOLFIRI. Extensive lymph node dissection of gastric region may be useful for advanced transverse cancer.