Genital carcinomas are associated with human papillomaviruses, and the viral DNA is frequently integrated in the host cell genome. Recurrent chromosomal alterations are genetic markers for specific tumor phenotypes. To demonstrate that papillomavirus DNA integration is indeed a recurrent chromosomal aberration, we mapped two independent papillomavirus integration sites in the human 12q14-15 region, one containing HPV16 DNA and the other HPV18 DNA. The two HPV integration sites map approximately 10 kbp from each other within the cosmid LLNL12NCO1-196E1 clone. The integration site corresponding to HPV16 DNA in SK-v cells is proximal to the 5' end of a DNA segment known to be rearranged by integration of HPV18 DNA in another cervical carcinoma cell line, SW756. Both integrations are located in the PAL2 locus within the uterine leiomyoma cluster region of translocation.