Varicella-zoster virus has developed a complex strategy that allows it to remain latent in the body and avoid destruction by the immune system. Although varicella and zoster have been recognized since antiquity, several new clinical syndromes--including chronic chickenpox with persistent verrucous lesions and disseminated varicella without skin lesions--have been noted in patients with AIDS. Acyclovir has been the mainstay for treating severe varicella-zoster virus infections; however, newer antiviral agents, including valacyclovir and famciclovir, have expanded therapeutic options for treating adults with herpes zoster. The recently licensed live attenuated vaccine for varicella-zoster virus is effective in preventing chickenpox, and the vaccine's ability to stimulate immunity in seropositive adults suggests a promising strategy with which to modify the course of herpes zoster.