Expression of immunocytochemically detectable markers in 100 cases of laryngeal carcinomas, homogeneous for staging and treatment, was correlated with clinical evolution of the disease. Follow-up for a minimum of 5 years was obtained in all cases. Paraffin sections were re-cut and stained in immunoperoxidase with monoclonal KL1, detecting medium-to-low molecular weight keratins, and with monoclonal HMFG2, revealing a surface glycoprotein. Expression of KL1-related antigen did not correlate with prognosis, whereas cases extensively positive for monoclonal HMFG2 (more than 50% cells stained) had a significantly better recurrence-free rate. In a group of tumors classified as Grade 3 (histologically poorly differentiated) and expressing a low degree of HMFG2-detectable surface glycoprotein (less than 50% cells stained), a high rate of recurrences (93%) was observed. This study indicates that the combined use of morphologic and biologic (immunohistochemical) criteria may constitute an independent parameter of primary importance in predicting the evolution of laryngeal carcinomas.