Multiple tissue samples obtained from sections cut by Michaels and Gregor's method obtained from 21 consecutive total laryngectomies for squamous cell carcinoma were studied for intratumoral DNA content heterogeneity or homogeneity. Concordant DNA ploidy was manifested in all samples of five (23.8%) carcinomas (two diploid and three aneuploid), while 16 carcinomas (76.2%) demonstrated a variable DNA ploidy (diploid and aneuploid). Analysis of cellular proliferative activity demonstrated remarkable intratumoral stability in both concordant and discordant carcinomas. These data indicate there is a considerable heterogeneity of DNA ploidy but the proliferative rate is relatively stable within the carcinomas. Clinical implications of our findings are also presented.