The development of a model of induced recurrent herpes simplex virus disease would facilitate studies of the mechanism(s) responsible for reactivation of latent virus. The guinea pig model of genital herpes is characterized by a selflimited primary infection, the establishment of a latent infection in sensory ganglia, and the subsequent development of spontaneous recurrent genital infections. This study reports that exposure of latently infected female guinea pigs to ultraviolet radiation results in the induction of recurrent genital herpes simplex virus infections in approximately 60% of animals. Furthermore, there was a dose-response relationship between ultraviolet irradiation and ability to induce recurrent disease. This model should prove useful in further investigations of the pathophysiology of herpes simplex infections.