Four of the seven human herpesviruses are recognized to replicate in the female genital tract and may be transmissible to sexual partners and newborn infants. Several of these viruses have also been implicated in the etiology of various human cancers, including tumors of epithelial cell origin. Human herpesvirus 6 (HHV-6) is a newly identified herpesvirus that causes exanthem subitum. The pathogenicity of HHV-6 within the genital tract is largely unexplored. Acellular vaginal secretions from 29 women attending a sexually transmitted diseases clinic were examined for the presence of HHV-6 DNA sequences by polymerase chain reaction. Three samples (10%) were consistently positive for HHV-6 DNA. Since HHV-6 DNA is shed in the genital tract of some women, it is possible that infectious virus is transmissible through sexual contact and to newborn infants by perinatal spread.