Cystic and cavitary lung lesions constitute a spectrum of pulmonary diseases diagnosed in both children and adults. Cysts and cavities are commonly encountered abnormalies on chest radiography and chest computed tomography. High-resolution computed tomography (HRCT) of the chest frequently helps define morphologic features that may serve as important clues regarding the nature of cystic and cavitary lesions of the lung. Occasionally, the underlying nature of the lesions can be readily apparent as in bullae associated with emphysema. Cystic and cavitary lung lesions can be diagnostic challange. Although many patients with cystic and cavitary lung lesions have a known underlying disease, in many cases the considerable overlap in morphologic features of these lesions tenders transthoracic needle biopsy necessary to establish the correct diagnosis.