Infection is the leading cause of morbidity and mortality in immunocompromised patients such as hematopoietic/solid organ transplant recipients and individuals with human immunodeficiency virus. Community respiratory virus infections are increasingly recognized as a significant threat to these patients. This article reviews current information in the clinical field of community respiratory viruses, including several newly discovered respiratory viruses. Respiratory syncytial virus, influenza viruses, parainfluenza viruses, and adenoviruses cause the most serious disease in immunocompromised hosts, but other respiratory viruses are becoming increasingly appreciated as a cause of both upper and lower respiratory tract disease. The clinical impact of these new viruses, including human metapneumovirus, non-SARS human coronaviruses, and human bocavirus, is not yet clear. Modern molecular technology has made the discovery of new viruses possible; the use of these new technologies in direct patient care is not yet standard but is becoming increasingly utilized. Clinicians should appreciate the potential for the development of antiviral resistance to influenza antivirals in immunocompromised patients.