Previous reports have shown specific binding characteristics of peanut lectin to a variety of lymphatic and epithelial tumors. This study demonstrates the presence of lectin binding sites on cell membrane of laryngeal cancer cells, but not on adjacent normal epithelial linings. It also demonstrates the presence of glycoconjugates responsible for lectin adherence in fetal larynges. The Thomsen-Friedenreich antigen is a glycoprotein structure participating in the structure of the MN blood group antigen. It is also the structure that binds the peanut agglutinin. Perhaps this antigen, which we found on fetal larynges as well as on malignant laryngeal epithelial lining, is another oncodevelopmental antigen.