Bronchiectasis is important because (1) it predisposes the patient to infection; (2) it may be accompanied by increased bronchial blood flow and hemoptysis; (3) when widespread, it may be associated with significant airway obstruction; and (4) when focal, it may simulate neoplasms and other diseases. The widespread use of computed tomography (CT) for evaluation of lung diseases has revealed that bronchiectasis is common--even in patients who do not have clinical or plain radiographic suspicion of bronchiectasis. The pathology, pathogenesis, and radiographic findings are presented herein.