Colorectal cancer has been associated with the expression of different tumor antigens; CEA and CA 19-9 have largely been studied and their high serum values are coincident with the presence of tumor mass. The present report shows results obtained after analysing this tumor location with a group of monoclonal antibodies (MAbs) raised against colonic glycolipid, CEA, CEA/NCA, MUC-1 and Le(y) hapten, Results have demonstrated an heterogeneous antigenic expression of this colorectal cancer since a positive immune reaction was observed in the different assays with these MAbs.