In our experience with fluoroscopically guided flexible fiberoptic bronchoscopy (FFB), transbronchial biopsy, bronchial brush, bronchial washing (BW) and sputum cytology (SC) in 101 patients with solitary pulmonary nodules (SPN) less than 6 cm in diameter (without endobronchial tumor), a specific diagnosis was reached via FFB in 36 cases. The diagnostic yields in primary lung malignant lesions (PLM), metastatic lesions and benign SPN were 58 percent, 28 percent and 10 percent, respectively. Size affected diagnostic efficiency considerably, with a 12 percent yield in lesions under 2 cm, a 40 percent yield in lesions 2 to 4 cm and a 63 percent yield in lesions over 4 cm. BW and SC (prebronchoscopic) did not contribute enough information to justify their cost. FFB directly affected therapy in 17 patients who were not thoracotomy candidates and may have influenced the decision for surgical treatment in another 19 patients diagnosed as having PLM. In 65 patients results of FFB were negative and the procedure did not appear to directly affect subsequent management because malignancy was not ruled out.