Background: Colorectal cancer (CRC) represents a significant portion of cancer incidences globally, necessitating effective biomarkers for its diagnosis and management. Serum Carcinoembryonic Antigen (CEA) has been extensively studied as a potential marker for the diagnosis, staging, and monitoring of colorectal cancer. This study aims to elucidate the correlation between preoperative serum CEA levels and the pathological staging and grading of colorectal malignancies, providing insights into its utility as a prognostic marker. Materials and Methods: The study conducted a prospective analysis involving 50 patients diagnosed with colorectal cancer at King George Hospital, Visakhapatnam. Serum CEA levels were measured preoperatively and correlated with the TNM staging and histopathological grading of the tumors obtained postoperatively. Data analysis aimed to assess the sensitivity and specificity of CEA in predicting tumor burden and stage. Results: The results showed that elevated CEA levels were significantly associated with advanced disease stages and higher tumor grades. The majority of the patients with elevated CEA levels had tumors classified as T3 or T4, N1 or N2, and M1, indicating more advanced and aggressive disease. The sensitivity of CEA in detecting colorectal malignancies was found to be 88%. Conclusion: Serum CEA levels correlate with the severity of colorectal malignancies, with higher levels associated with advanced pathological stages and poorer differentiation of tumors. While CEA is not suitable as a standalone screening tool due to its moderate sensitivity, it proves valuable in conjunction with other diagnostic and monitoring techniques.