Four hundred forty-seven needle biopsies of the lung were carried out on 348 patients in a nonhospital outpatient setting. There were no fatalities or serious complications. A reliable working diagnosis was obtained in 74% of patients (86% true positive for malignancy). Diagnostic thoracotomy was avoided in 31%, and the diagnostic interval was shortened in most. Impressive economic benefits resulted. Careful postbiopsy evaluation revealed pneumothorax in 41% of patients, with 10% requiring chest tube drainage, usually on an ambulatory basis. With management of the infrequent complications by the radiologist, outpatient needle biopsy of the lung can be safe, reliable, and highly cost effective.