Thirty-eight squamous carcinomas of the mobile tongue were flow cytometrically analyzed for their DNA content, and the results correlated with clinicopathologic parameters and patient survival. Tumor size (p = 0.01), depth of invasion (p = 0.05), histologic differentiation (p = 0.03), ploidy pattern (p = 0.01), and S-phase (p = 0.001) showed significant correlation with patients' clinical outcomes in univariate analyses. A multifactorial regression analysis of all significant parameters indicated that S-phase percentage and depth of tumor invasion were independent prognostic factors in this cohort.