Varicella-zoster virus (VZV) infections, the cause of chickenpox and shingles, are usually benign but are associated with morbidity and mortality, especially in immunocompromised hosts. Significant advances have been achieved in the treatment of VZV infections. In immunocompromised patients, both vidarabine and acyclovir have proved useful for the therapy of chickenpox and herpes zoster. Acyclovir, administered intravenously, is the treatment of choice for these infections. Both chickenpox and herpes zoster in the normal host are amenable to therapy with orally administered acyclovir. For older individuals with herpes zoster, acceleration of cutaneous healing can be accomplished at dosages of 800 mg five times a day for 10 days. Acyclovir therapy of chickenpox is recommended for adolescents and young adults with infection. In the future, improved therapies for VZV infections may include such newer antiviral drugs as bromo- vinyl arabinosyl uracil and acyclovir prodrugs. © 1992 by The University of Chicago.