A 29-year-old man underwent bilateral lung transplantation and received maintenance immunosuppressive therapy. He was readmitted 11 months later with symptoms of cough, sneezing, and rhinorrhea. The physical examination was normal. Laboratory results were significant for a reduction of FEV1 and an interstitial infiltrate on chest films. The patient had recently undergone bronchoscopy for rejection surveillance, and 2 days before admission the bronchoalveolar lavage cultures returned positive for respiratory syncytial virus. The patient was treated with aerosolized ribavirin with complete resolution of symptoms. Respiratory syncytial virus must now be included in the list of pathogens causing pneumonia in the lung transplant recipient.