Cytomegalovirus (CMV) continues to account for a substantial percentage of the morbidity and mortality that follows organ transplantation. The three major consequences of CMV infection of the lung are CMV pneumonitis, pulmonary superinfection with opportunistic pathogens, and indirect CMV-mediated injury to the lung. In the last decade, considerable progress has been made toward elucidating risk factors for CMV pneumonitis, with rapid detection of CMV in respiratory specimens and other clinical samples and with the use of antiviral chemotherapy and immunoglobulin to prevent and treat CMV pneumonitis after transplantation. With the introduction of preventive ganciclovir therapy and a better understanding of the immunology of CMV in transplant recipients, there has been a significant change in the management of CMV pneumonitis. This article discusses the effect of these advances on patient outcome after transplantation and the challenges for the next decade.