In June 2010, a 62-year-old man underwent right hemicolectomy with transverse colostomy for advanced ascending colon cancer with peritoneal dissemination(pSE, pN3H0P3M0, fStage IV, R2). One month after surgery, systemic chemotherapy (combination regimen of oxaliplatin injection and S-1 per os; SOX regimen) was introduced for the residual lesion. After completing 4 courses of the SOX regimen, peritoneal dissemination was not detected by abdominal computed tomography. In the same month, laparotomy was performed to close the temporary stoma, in which the lack of peritoneal dissemination was confirmed. After the stoma was closed, although no chemotherapy was administered because of patient preference, he has been free from relapse of the peritoneal dissemination, according to his latest follow-up examinations in June 2012. In this case, resection of the primary lesion immediately followed by a short period of systemic chemotherapy resulted in good control of peritoneal dissemination. Because the effect of these therapies allowed him to undergo stoma closure and to refuse further chemotherapy, he has been able to maintain his quality of life. In cases of reduction surgery for advanced colorectal cancer with unresectable peritoneal dissemination, a minimal resection including the primary lesion to avoid perioperative complications, which could permit the immediate start of systemic chemotherapy, could result in good control of peritoneal dissemination.