A pulmonary lesion usually poses a diagnostic problem requiring a swift solution. Percutaneous fine-needle aspiration biopsy (NAB) technique yields a high percentage of correct diagnosis. However, this procedure is often underestimated and its indication vaguely known. Experience with 185 NAB in 175 patients is reviewed. One hundred and ten procedures were performed in hospitalized patients and 75 in an outpatient setting. Forty-four percent of cases in the whole series have had a previous negative fiberoptic bronchoscopy examination (FOB). Sixty-five percent were peripheral solitary pulmonary nodules, 54 percent of which were less than 2 cm lesions. The majority of NAB were performed under imaging guidance utilizing 20-23 gauge Chiba needles. High resolution fluoroscopic guidance was employed in 86 percent of cases, Computed Tomography (CT) in 11 percent and Ultrasonography in 3 percent. Specific cytologic diagnosis were obtained in 87 percent of the procedures done in hospitalized patients and 86.3 percent in ambulatory cases. In both groups, a 69 percent of neoplastic lesions were obttained. Post-biopsy pneumothorax was detected in 15 percent in each series. Only 3 patients in the whole series required the placement of a chest tube. To date, no needle tract seeding has been observed. A 9.3 percent and 10 percent of false negative results were recorded in both series, respectively. In this report, the complication rate is low and showed no statistical significant differences between the hospitalized and the outpatient groups. The latter resulted in less operative costs. Besides, TC guidance increases about 80 percent the operative expenses without offering a significant diagnostic yield. We conclude that NAB under fluoroscopic guidance in an outpatient basis is a reliable, safe, expeditious and cost effective diagnostic tool in small peripheral pulmonary lesions.