We retrospectively evaluated records of 1598 fiberoptic bronchoscopies (FBs) performed on 1,391 patients (PTs) between jan 1, 1986 and Dec 31, 1990. We found a progressive increase from 11 percent to 20 percent in the use of repeated fiberoptic bronchoscopy (RFB). Of the 254 RFBs, 151 were done in PTs with known or suspected intrathoracic malignant neoplasms. The 78 (of 151) RFBs performed in PTs with previously diagnosed malignant neoplasms were used to guide additional therapy. The other major indication for RFB (67 of 151) was to evaluate new suspicious lesions that had not been diagnosed on the initial FB. RFB specimens were positive in 36, false-negative in 24, and true-negative in 7 PTs. For some PTs, RFB could probably have been avoided if at initial FB physicians had (1) used fluoroscopy to direct transbronchial lung biopsies in PTs expected to have normal airways, (2) performed transbronchial needle aspiration in all PTs with extraluminal disease or mediastinal adenopathy, and (3) obtained bronchial biopsy specimens from all PTs with endobronchial lesions. In PTs whose initial FB specimens were nondiagnostic despite visualization of endobronchial or extraluminal abnormalities, RFB was associated with a significant diagnostic yield and obviated the need for more morbid, surgical staging procedures.