Immunodeficiencies in children may be caused by primary immunodeficiency syndromes or can result from secondary disorders of immune regulation. Thoracic complications in immunocompromised children are frequent and may vary according to the type of the immunodeficiency. Imaging plays a pivotal role in detection and distinction of the variety of sequelae. It is important for the radiologist to understand both the spectrum of pediatric immune disorders, and the mechanisms underlying these disorders.