Objective: To evaluate the diagnostic significance of CEA specific antibodies in the serum of patients with gastrointestinal malignancies. Methods: The CR4 levels were tested by an.The circulating antibodies against CEA were tested by an enzyme-linked immunoassay (ELISA) .The specificity of the CEA antibodies was carried out by an inhibition assay. Results: The CEA was elevated( ≥15 ng/ml) in 21 patients with gastrointestinal malignancies(30.9%) and in 1 patient with benign gastrointestinal conditions( hyperplastic polys, ulcers, pancreatitis, etc)(3.3%) .Anti-CEA IgG antibodies were detected in 24 patients with gastrointestinal malignancies(35.3%) and in 1 health individual (2.5%).Conduskm: In this study ,a high number of gastrointestinal malignancies patients have circulating CEA specific antibodies in their sera and these antibodies may be used as diagnostic markers.