Background: We know that inflammation is related to colorectal cancer prognosis and to the onset of postoperative infections. Objective: This study aimed to understand the relationship between preoperative inflammation and the prognosis of colorectal cancer and to elucidate whether the impact of inflammation on cancer prognosis was related to an increased risk of surgical infection or was independent of it. Methods: Patients who underwent elective colorectal cancer surgery between November 2011 and April 2014 were included in a prospective database (IMACORS). Preoperative c reactive protein was collected for each patient. Patients were followed up according to the French national guidelines. A cut-off of preoperative CRP of 5mg/L was chosen. Clinical characteristics were compared according to CRP using Chi2 and Mann-Whitney tests. The Overall Survival (OS) and Disease-Free-Survival (DFS) were compared by Kaplan-Meier curves. A Cox proportional hazards regression model was applied to perform a multivariate analysis of OS and DFS's predictors. Results: A total of 254 patients were included. The median age was 68 years old. The median follow up was 41.8 months. The overall median preoperative CRP was 5mg/L. Preoperative CRP was significantly associated with N status; CRP being significantly higher among patients with colonic cancer and with patients who didn't receive a neoadjuvant treatment. Multivariate analyse revealed that preoperative CRP is an independent prognostic factor of OS and DFS respectively (HR=2.34 (1.26-4.31), P=0.006 and HR=1.83 (1.15-2.90), P=0.01). Conclusion: Preoperative inflammation measured by CRP is independently related with overall and disease-free survival of colorectal cancer.