Both preoperative serum albumin (ALB) and carcinoembryonic antigen (CEA) were previously reported as useful prognostic factors in colorectal cancer (CRC); however, the ALB to CEA ratio (ACR) and their individual prognostic efficacies have been less studied. In this study, a total of 156 CRC patients staged I-IV were retrospectively enrolled. Patients were divided into ACR-low or ACR-high subgroups, and the differences in progression-free survival (PFS) and overall survival (OS) were conducted by Kaplan-Meier curves, log-rank test and Cox proportional model. As a result, a total of 31.41% (49/156) of patients presented with ACR-low disease, and these patients had tumors with advanced T stages (T3 + T4) (P<0.01), larger tumor diameters (P<0.01) and distant metastases (P = 0.01) and a relatively lower lymphocyte to monocyte ratio (LMR) (P<0.01). The ACR was significant in predicting survival. When 5.98 was used as the cutoff point, it had a sensitivity of 58.50% and 61.50% and a specificity of 83.50% and 80.50% for PFS and OS, respectively. ACR displayed a superior prognostic efficacy than other tested markers for both PFS and OS (except LMR). Patients in the ACR-low group displayed significantly worse PFS (log rank = 35.75, P<0.01) and OS (log rank = 29.68, P<0.01) than those in the ACR-high group. Finally, ACR was an independent prognostic factor for both PFS (HR = 0.31, 95% CI: 0.17–0.56, P < 0.01) and OS (HR = 0.33, 95% CI: 0.16–0.66, P < 0.01). For conclusion, the ACR was a robust prognostic factor in CRC, and patients with a relatively low preoperative ACR had significantly worse survival.