Using the six lectins PNA, SNA, WGA, UEA-1 Amaranthin, and MAA, a cytochemical study was performed to observe the expression of glycoconjugates in squamous cell carcinomas of the larynx in 14 patients and in 3 normal laryngeal epithelia. SNA (Sambucus nigra agglutinin) failed to stain the cytoplasm in normal squamous epithelium of the larynx, but the cytoplasm of the epithelial dysplasia and carcinoma cells reacted to SNA, showing more intensely stained cytoplasma of carcinoma as compared to those of the epithelial dysplasia. PNA (Peanut agglutinin) specifically stained cell membranes of middle layer and basal cells in the normal squamous epithelium and epithelial dysplasias, but in squamous cell carcinomas, a lack of cell membrane staining of various degrees was noted. There was a similarity in the other lectin staining expressions in the normal controls and epithelial dysplasia and carcinoma. The expression of these six lectins was not related to the TNM-classification. Lectin staining may be a useful marker in either early diagnosis of cancer or the assessment of cellular differentiation.