Objective To analyze the application value of preoperative controlling nutritional status (CONUT) score for evaluating the follow⁃up prognosis in colorectal cancer (CRC) patients after radical resection. Methods A total of 186 patients with CRC diagnosis in Lishui Hospital from February 2014 to February 2016 were retrospectively summarized. According to the preoperative CONUT score, they were divided into high⁃CONUT group (≥ 3) and low⁃CONUT group (≤ 2). Kaplan⁃Meier curve was used to compare the 5⁃year overall survival rate (OS). Univariate and multivariate Cox regression were used to analyze the risk factors of OS. Results 186 patients were divided into high⁃CONUT group (n=101) and low⁃CONUT group (n=85). In high⁃CONUT group, the age was older, body mass index (BMI) was less, prognostic nutritional index (PNI) was lower, neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) were higher, TNM stage, tumor diameter and serum carcinoembryonic antigen (CEA) level were higher, too(P<0.05). The OS of high⁃CONUT group was lower than that of low⁃CONUT group, and the same to the patients in different TNM stages (P<0.05). Regression analysis showed that age ≥ 60 years, BMI<18.5 kg/m2, TNM stage ( Ⅱ b ~ Ⅲ) and CONUT score ≥ 3 were independent risk factors to OS (P<0.05). Conclusion Higher preoperative CONUT score may indicate the risk of poor prognosis in patients with CRC after radical resection. CONUT score can provide important reference for clinicians to formulate appropriate nutritional intervention plan.