Peritoneal dissemination is one of the treatment failures following gastric cancer surgery. We present a case with very early peritoneal recurrence, detected 8 days following curative surgery. A 39-year-old man, with Borrmann-4 advanced gastric cancer with signet ring cell type, underwent curative open total gastrectomy. However, focal peritoneal nodules on the left side of the diaphragmatic surface, which did not exist at the initial operation, were incidentally found during the reoperation for a postoperative intestinal obstruction via a laparoscopic approach. The pathologic result of the biopsied nodule revealed signet ring cell carcinoma. The patient underwent combination chemotherapy for several months without tumor regression. He suffered from intestinal obstruction again due to carcinomatosis peritonei, and died 9 months following initial surgery. Through this case report, we can carefully suspect that very early progression of cancer cells to carcinomatosis can occur in just several days after an operation.