Guinea pigs were infected with herpes simplex virus (HSV) intravaginally and then sacrificed during latent infection. Virus was recovered from the ganglia, spinal cord and genital tissues by co-cultivation after 1-6 weeks in culture. The virus could not be recovered from the genital tract during the first week of co-cultivation, nor from homogenized genital tissue. Cultivation of genital tissues with acyclovir did not reduce the recovery of HSV. Thus, HSV appeared to establish a truly latent infection in the genital tract and not a persistent infection as previously described.