Eleven pure adenocarcinomas of the cervix were analyzed for human papillomavirus (HPV) types 6, 11, 16, 18 and 31 by Southern blot hybridizations. Seven tumors were positive for papillomavirus DNA. Five hybridized to the HPV 18 specific probe and two tumors hybridized to HPV 16. All tumors were negative for HPV 6/11 and 31, and no additional tumors became positive with hybridizations under nonstringent conditions to a mixture of HPV probes. No papillomavirus DNA was detected in 11 noncervical malignancies or in six hysterectomy specimens in which cancer was not present. The histopathologic and clinical features of the patients were correlated with the presence of HPV. The women with papillomavirus DNA in their adenocarcinomas tended to be younger (mean age, 37.3) than those that were negative for HPV (mean age, 49.0). The findings suggest that papillomaviruses may be an etiologic factor in the development of some adenocarcinomas of the cervix.