Cytomegalovirus (CMV) is frequently isolated from respiratory secretions of human immunodeficiency virus (HIV)-infected patients. Even in the presence of histopathologic evidence of CMV cytopathic abnormalities, the true clinical significance of CMV pneumonitis is not well established. Airways disease is increasingly recognized in HIV-infected patients, but its etiology is unclear. We describe an HIV-infected patient who presented with fever, wheeze, and micronodular interstitial infiltrates and developed severe hypercapnic and hypoxemic respiratory failure. Open lung biopsy showed necrotizing bronchiolitis with cytopathic changes characteristic of CMV infection; no other pathogens were isolated. He responded well to treatment with ganciclovir.