We reported a case of P1CY1 gastric cancer with intraperitoneal chemotherapy after surgery for more than four years. The patient was a 69-year-old male who had suffered from Type I+Type 0 IIc, T3 gastric cancer. He underwent total gastrectomy with D2 dissection. Operative findings revealed P1CY1, and it resulted in non-curative resection. After surgery, combined chemotherapy with low-dose CDDP intraperitoneal administration and UFT, and then combined chemotherapy with paclitaxel and 5-FU were performed. He also underwent palliative surgery for intestinal obstruction resulting from carcinomatous peritonitis. He achieved long-term survival by multidisciplinary therapy of chemotherapy and surgery.