A 66-year-old man underwent a curative operation for advanced gastric cancer (T4aN0M0, Stage IIB). A gastric cancer recurrence with paraaortic lymph node (PALN) metastasis was diagnosed fifteen months after the operation. Systemic chemotherapy was initiated, using a regimen of S-1/CDDP. After 7 courses, abdominal computed tomography (CT) examination indicated the regression of PALN swelling. However, peritoneal dissemination was detected in the neighborhood of the right kidney. S-1/docetaxel (S-1/DOC) was selected as the second-line chemotherapy. After 3 courses, the peritoneal dissemination could not be detected. Five years since the curative operation, the patient has been doing well, with no signs of recurrence. In summary, we successfully treated a case of peritoneal dissemination from gastric cancer with S-1/DOC chemo- therapy.