Thus, the aim of this study was (1) to evaluate postoperative morbidity, mortality and surgical oncological outcomes in colorectal cancer patients with peritoneal metastasis; (2) to compare oncological and postoperative outcomes of colon cancer patients with peritoneal metastasis and rectal cancer patients with peritoneal metastasis; and (3) to assess the prognostic value of the modified Glasgow Prognostic Score (mGPS) and CRP–albumin ratio (CAR). Here, CRP is linked to rectal cancer.