Adenoviruses are ubiquitous DNA viruses that cause a wide variety of illnesses, including pneumonia, in children and adults. Forty-one distinct human sero-types have been identified, yet only about six of these serotypes are associated with the majority of the cases of adenovirus-induced pneumonia. Adeno-virus infection accounts for up to 20% of childhood pneumonias, primarily in those children younger than 5 years of age, but such pneumonias occur infrequently in the nonmilitary adult population. Roentgenologic findings include patchy or diffuse infiltrates, consolidation, and occasionally, pleural effusion. Histopathologic examination of lung tissue frequently reveals a necrotizing bronchitis and bronchiolitis. Such pulmonary destruction results in abnormal pulmonary function in up to 60% of these patients. Mortality rates vary with the population studied and the etiologic serotype, reaching as high as 60% in immunocompromised patients and 15% to 20% of the children with adenovirus type 7 pneumonia. Diagnosis requires either virus isolation or detection of a four-fold or greater rise in serum antibody over a 2- to 3-week period of time. Treatment consists primarily of symptomatic care, while prevention of infection relies upon the selected use of serotype-specific, enteric-coated, live adenovirus vaccines.