Eighty-five patients with squamous that were cell carcinoma of the supraglottis treated surgically in the Department of Otolaryngology at the Marqués de Valdecilla Hospital in Santander (Spain) over a 10-year period from January 1, 1978 to December 31, 1987 were studied retrospectively. In 81 cases a flow cytometric study was made from the surgical specimen included in paraffin blocks, to determine the DNA index and the percentage of cells in the S phase of the cellular cycle. An statistical analysis was made to determine the correlation between these parameters and survival was analyzed using the Kaplan-Merer method. Survival curves were compared using the log-rank test. In 67 cases (82.7%) DNA content was diploid and in 14 cases (17.3%) it was aneuploid. The percentage of cells in S phase was 3.8 and 55.4, with a mean value of 15.19. Comparison of with the five these parameters years survival showed no statistical differences between groups, although tumors with more than 19% S phase had worse prognosis (p < 0.1) and tumors in advanced stages were more frequently aneuploid and had higher S phase values (p = 0.1).