We recently encountered a rare case where gastric cancer developed in the long-term postoperative stage after coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA) and distal partial gastrectomy was performed to treat the cancer. The patient was a 64-year-old man. In November 2001, he underwent three-vessel CABG, involving bypassing between the right coronary artery (RCA) and the RGEA, to treat an old myocardial infarction. In May 2003, he was admitted to our hospital because of exacerbation of diabetes mellitus and anemia. Gastric endoscopy revealed gastric cancer affecting the pylorus. Preoperative abdominal angiography showed the RGEA graft remained well patent. In June 2003, he underwent distal partial gastrectomy and regional lymph node dissection. Because the RGEA had been freed adequately to the point of bifurcation of the gastroduodenal artery during the previous CABG, the RGEA graft was preserved during distal partial gastrectomy. When the RGEA is used for CABG, it seems advisable to free the RGEA adequately to a point of bifurcation of the gastroduodenal artery. If done so, regional lymph node dissection around the RGEA is easier to perform when gastric cancer has occurred in these cases, eventually reducing the risk for injury of the graft. Following CABG with the RGEA, it seems essential to perform periodical checks for gastric cancer to facilitate early detection of gastric cancer. The necessity of close follow-up of these cases is endorsed by the fact that healing of gastric cancer by endoscopic mucosal resection (EMR) is highly probable if the cancer is detected at early stages.