We reviewed the records and chest roentgenograms of 133 patients who underwent flexible fiberoptic bronchoscopy (FFB) for a solitary pulmonary nodule (SPN), defined as a circumscribed density less than or equal to 4 cm in diameter surrounded by aerated lung with no associated radiologic abnormalities. Each patient had a complete medical examination followed by FFB with collection of bronchial washings and brushings, transbronchial biopsy (when technically possible), and postbronchoscopy sputum collection. Subsequently 50 patients underwent percutaneous needle aspiration (NA) and 32 diagnostic thoracotomy (DT). Eight-two (62 percent) of the evaluations resulted in a histologic diagnosis. Prebronchoscopy sputum was diagnostic in three patients. Of 143 FFBs performed, 27 (19 percent) were diagnostic, and 26 were the first procedure of the evaluation to provide a diagnosis. Following nondiagnostic FFB, a diagnosis was provided by 50 (36 percent) NA, 32 of 32 (100 percent) DT, and 3 of 3 (100 percent) cervical and mediastinal node biopsy procedures. For both FFB and NA, there was a strong correlation between nodule size and diagnostic yield. FFB visualized a vocal cord lesion in five patients and an endobronchial mass in five. The combination of FFB and NA provided a diagnosis in 45 of 51 (88 percent) patients ultimately proved to have a malignant SPN. Neither procedure was diagnostic in any of the 24 patients with a benign SPN. We conclude that FVFB and NA have complementary roles in the evaluation of SPN.