Cytomegalovirus pneumonia is a viral pneumonia caused by infected cells, characterized by the formation of giant A-type eosinophilic intranuclear and intracytoplasmic inclusion bodies, most of which are asymptomatic latent infections, but in immunocompromised and infants it can cause severe lung infections leading to death. In recent years, with the introduction of bone marrow and organ transplantation and the increasing number of AIDS patients, cytomegalovirus has become the most common causative agent in both conditions. The diagnosis is confirmed on the basis of clinical manifestations and laboratory tests and X-rays.