To evaluate the accuracy of clinical staging of supraglottic carcinomas, a retrospective histopathological study of larynges from 53 patients who had undergone total laryngectomy was adopted. All larynges were processed as whole-organ serial sections in coronal plane. The results showed that clinical underestimation had been made in 24.5% of all laryngeal cancer cases. Clinical underestimation occured in 54.5%, 33.3% of T2, T3 laryngeal cancer cases, respectively. There was no overestimation in clinical staging. The important factors that affected clinical underestimation were invasion of the pre-epiglottic space and thyroid cartilage. It is suggested that the pre-epiglottic space should be resected in early supraglottic carcinoma. The thyroid cartilage involvement should be suspected in laryngeal cancer with extensive invasion of anterior commisure or extensive invasion of the paraglottic space accompanied by cartilage ossification.