The clinical staging systems for laryngeal cancer is limited as a prognostic indicator because of different biological characteristics of cancer in this region and variable microenvironment depending on subsites. For determining prognostic indicators, the authors performed immunohistochemical staining of epidermal growth factor receptor(EGFR), p53 protein, and retinoblastoma gene protein(pRB) in 40 cases of surgically treated squamous cell carcinomas of the larynx. The results are as follows : 1) The positive rate of p53 protein expression showed a correlation with clinical stages, T stages, N stages, extracapsular spread of metastatic neck nodes, pathologic grades, and recurrences or distant metastases. 2) The negative rate of pRB expression showed a correlation with invasiveness as seen in supraglottic cancers, clinical stages, T stages, extracapsular spread of metastatic neck nodes, pathologic grades, recurrences or distant metastases, and treatment failures. 3) The rate of EGFR expression showed correlations with extracapsular spread of metastatic neck nodes and recurrence or distant metastases. In conclusion, expression rates of p53 protein and pRB not only reflected well the biologic behavior of laryngeal squamous cell carcinomas, but correlated closely with the tumor factors of laryngeal squamous cell carcinomas. However these indicators related with tumor factors in complicated patterns. Therefore, the immunohistochemical study for p53 and pRB may be considered as an adjuvant method for supporting the reliability of tumor factor as a prognostic indicator of laryngeal squamous cell carcinomas.