Seven biopsies from different carcinomas of the tongue were analyzed for human papilloma virus (HPV) sequences by Southern blot analysis. After hybridization with various types of human papilloma viruses, 1 tumors were found to be positive. Whereas DNA from one tumor hybridized with HPY 2 DNA under conditions of high stringency, the 2 other positive biopsies contained HPV 16 DNA. All positive tumors revealed high copy numbers of the respective DNA. The cleavage pattern of the HPV-2-positive tumor differed from the established HPV 2 prototypes. Minor differences from the HPV 16 prototype were also noted in one of the HPV-16-positive tongue carcinomas.