Background & Aims: Colorectal cancer is one of the most common cancers and one of the leading cause of morbidity and mortality worldwide. Accounting that the risk of colorectal cancer is associated with blood sugar indices as well as the role of CEA in the prognosis of patients with colorectal cancer, this study was fulfilled to determine the relationship between serum level of CEA and HOMA2-IR in colorectal patients. Materials & Methods: In this case-control study, 40 colorectal cancer patients and 40 healthy subjects, as the control group, were included. Serum levels of CEA, insulin, and fasting blood sugar were measured in all participants. The HOMA2-IR index was calculated based on the standard formula. Data were analyzed using SPSS version 26 software. Results: The mean of CEA was 7. 08±, 1. 9 in colorectal patients and 2. 21±, 1. 5 in control group, and difference between them was significant (p = 0. 003). Totally, the mean insulin among patients with CEA below 3 and CEA equal or more than 3 was 11. 06±, 6. 9 and 14. 34±, 8. 28, respectively (p = 0. 026). Also, mean FBS for two groups were 110. 67±, 42. 7 and 135. 9±, 52. 5 (p = 0. 01) and mean of HOMA2-IR for two groups were 1. 49±, 0. 98 and 2. 04±, 1. 25, (P = 0. 011), respectively. All these differences between two groups were significant. Conclusion: colorectal patients had higher levels of CEA than the control group. The mean values of all three indices of insulin, FBS و and HOMA2-IR among patients with colorectal cancer were higher in both groups of patients with CEA below 3 and patients with CEA equal or more than 3 than control group. There was strong positive correlations between CEA with insulin, FBS, and HOMA2-IR indices in colorectal patients compared to the control group.