The authors attempted to determine whether the anatomic characteristics of thoracic lesions and the surrounding lung field, as assessed by the preprocedure chest computed tomography (CT) scan, can assist in predicting the yield of complications or positive results of pathologic examination resulting from percutaneous core-needle biopsies (PCNB). The pathologic diagnoses and procedural complications of 50 consecutive thoracic PCNBs (43 men, age range 19-81 years) performed under the guidance of a single operator (J.A.M.) were recorded. Prebiopsy chest CT findings, including the size, depth, location, and border appearance of the lesion, as well as presence or absence of adjacent emphysema, interstitial fibrosis, bullae, pleural effusions, and the age and smoking history of the patient were correlated with the biopsy results and any ensuing complications. The pathologic analysis in 42 patients (84%) was specific enough to positively impact patient management, with 29 malignant and 13 benign entities. The imaging variables that predicted obtaining adequate tissue for pathologic diagnosis were most importantly large size (especially >35 mm), although irregular lesion margins and increased depth were significant as well. Seven patients (14%) experienced a pneumothorax, only one of which (2%) was symptomatic and required thoracostomy. All patients experiencing a pneumothorax had CT evidence of emphysema or interstitial fibrosis and all biopsied masses in these individuals had spiculated borders, with six (86%) in an anterior location and only one involving the pleural surface. We conclude that the preprocedure CT scan can delineate several characteristics of both the patient and the lesion to be biopsied that can assist in predicting the rates of successful tissue retrieval or pneumothorax during PCNBs.