A 61-year-old woman who underwent lung transplantation developed severe respiratory syncytial virus (RSV) pneumonia and experienced respiratory failure requiring mechanical ventilation. She was treated initially with aerosolized ribavirin monotherapy; RSV hyperimmune globulin was later added to her regimen. Lung transplant recipients are acutely susceptible to respiratory infections, including community-acquired respiratory viruses. Respiratory syncytial virus is particularly difficult to treat in immunocompromised patients because of the lack of proved pharmaceutical agents and solid scientific evidence by which to guide therapy. The most important factor appears to be the early start of therapy; immunocompromised patients who develop RSV pneumonia and subsequent respiratory failure requiring mechanical ventilation have a mortality rate approaching 100%. This case report demonstrates the successful treatment of RSV pneumonia with the combination of aerosolized ribavirin and RSV hyperimmune globulin in a severely ill lung transplant recipient who required mechanical ventilation.