PURPOSE: To review the clinical features of common viral infections in the elderly and discuss diagnostic approaches, treatment options, and prevention strategies for these infections. EPIDEMIOLOGY: In patients ≥65 years of age the incidence rate of herpes zoster is 11.8 per 1000 person-years; of influenza-associated pulmonary and circulatory deaths, 0.983 per 1000 person-years; of respiratory syncytial virus infection, 15 per 1000 person-years in high-risk elderly patients and 9 per 1000 person-years in the healthy elderly. More than 90% of older adults are seropositive for herpes simplex virus and are at risk for reactivation herpes. Older adults account for ≥90% of deaths attributed to pneumonia and influenza. REVIEW SUMMARY: Waning cell-mediated immunity in elderly patients is associated with higher incidence and greater severity of viral infections. Herpes zoster and herpes simplex occur due to reactivation of latent virus and are associated with painful vesicular skin lesions. Treatment with acyclovir, valacyclovir, or famciclovir shortens the duration of viral shedding and hastens resolution of lesions. Adjunctive use of prednisone in herpes zoster reduces the incidence of postherpetic neuralgia. Influenza and respiratory syncytial virus afflict a large population or elderly patients each winter and may be associated with life-threatening pneumonia. Oseltamvir and zanamavir are effective treatment options for influenza, ana vaccination is indicated for all persons >65 years of age. There is no widely available antiviral treatment for respiratory syncytial virus; symptomatic treatment is indicated. TYPE OF AVAILABLE EVIDENCE: Nationally recognized treatment guidelines, meta-analyses, unstructured reviews, prospective cohort studies, and clinical trials. GRADE OF AVAILABLE EVIDENCE: Good. CONCLUSION: Viral infections are more common in the elderly and may cause substantial morbidity and mortality. Newer antiviral medications are effective and offer increased ease of administration and less toxicity than do older drugs.