Background: Preoperative serum albumin (ALB) and carcinoembryonic antigen (CEA) were useful prognostic factors in colorectal cancer (CRC); however, the ALB to CEA ratio (ACR) and their individual prognostic efficacies have been less studied. Methods: A retrospective study with 156 CRC patients staged I to IV was performed. The prognostic efficacy of ACR was estimated and subsequently compared with ALB, CEA, and other systemic inflammation markers, including the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR). Differences in progression-free survival (PFS) and overall survival (OS) were determined by Kaplan–Meier (K-M) analysis, and the risk factors for survival were calculated by the Cox proportional hazards model. Results: A total of 31.41% (49 of 156) of patients presented with ACR-low disease, and these patients had tumors with advanced T stages, larger tumor diameters and distant metastases, and a lower LMR. When 5.98 was used as the cut-off 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 individual ALB, CEA and NLR, LMR, and PLR for both PFS and OS (except LMR). Patients in the ACR-low group displayed significantly worse PFS and OS 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 < .01) and OS (HR = 0.33, 95% CI: 0.16−0.66, P < .01). Conclusions: ACR was a robust prognostic factor in CRC, and patients with a relatively low preoperative ACR would have significantly worse survival.