Bronchiectasis (BR) is a descriptive term for abnormal, irreversibly dilated, and often thick walled bronchi, usually associated with inflammation. Causes are varied but include cystic fibrosis, aspiration, post infectious airway obstruction, immune abnormalities, immotile cilia, posttransplantation states, and congenital bronchial lesions. Although BR is uncommon in children, it causes significant mortality when present. Following a period of presumed decline due to antibiotics and vaccines, BR may increase in prevalence because of AIDS, organ transplantation complications, and changing patterns of childhood immunization. As with adults, high resolution CT (HRCT) is the most useful imaging tool for diagnosis and evaluation of bronchiectasis in children.