An 82-year-oldwoman previously underwent total gastrectomy for gastric cancer at the age of 75 years. After 7 years of follow-up, a colonoscopy was performedto investigate the cause of constipation, which revealedan irregularity in the rectal submucosa. A colonoscopy-guidedbiopsy showedpoorly differentiatedad enocarcinoma, andthe immunohistochemical staining pattern showedMUC2(-), MUC5AC(+), CDX2(+), andCA1 25(-). FDG-PET showedintense uptake only at the rectum. Thus, laparoscopic high anterior resection was performed. Pathological findings showed that poorly differentiated adenocarcinoma and signet-ring cell carcinoma hadd evelopedmainly in the submucosa. In comparison with the immunohistological features of the previous gastric cancer, the rectal tumor hadsimilar morphological characteristics. The definitive diagnosis was rectal metastasis from gastric cancer. She has remained recurrence-free in the 20 months since this operation.