The Controlling Nutritional Status (CONUT) score is a marker of nutrition and is associated with poor survival in various kinds of cancers. However, no reports have yet compared risk factors for colorectal cancer recurrence using a nutritional index. We assessed the predictive value of the CONUT score compared with the modified Glasgow Prognostic Score (mGPS) and Prognostic Nutritional Index (PNI) in colorectal cancer (CRC) patients. We performed a retrospective cohort study of the medical records of 336 consecutive patients with stage I-I I I CRC who underwent curative resection at a single institution in 2012-2017. Univariate and multivariate analyses were conducted to identify prognostic factors associated with relapse-free survival (RFS) and overall survival (OS). The low CONUT score group exhibited higher RFS and longer OS compared to the high CONUT score group (82.2% vs. 63.3%, p = 0.002 and 95.5% and 86.2%, p = 0.005, respectively). The Akaike's information criterion values of each index for RFS and OS were superior in CONUT score (723.71 and 315.46, respectively) compared to those of PNI (726.95 and 316.52) and mGPS (728.15 and 318.07, respectively). The CONUT score was found to be a good predictor of RFS and OS in patients with resectable CRC.