Three cost-consequence models were developed for treatment of infections due to varicella-zoster virus (VZV) with acyclovir in immunocompetent patients--adult- and childhood-onset chickenpox, and herpes zoster (shingles) in adults. For chickenpox, separate models allow examination of differences in severity and impact of the disease for children and adults, as well as in the management of civilians and adults in military service. Each model includes direct medical costs, indirect costs and health-related productivity loss, symptom and quality of life impact, and model assumptions and conclusions. Alternatives of treatment and no treatment are addressed. Quality of life impact is conceptualized in terms of a quality-adjusted life-days decrement due to VZV symptoms of importance to the patient, such as pain, rash, and itching. As experience and data become available, alternative agents such as valacyclovir and famciclovir for the treatment of patients with herpes zoster should be included in the modeling process.