BACKGROUND: Ever since Flexible Fiberoptic Bronchoscopy was introduced into clinical practice, it has played an important role in both diagnosis and therapy of respiratory diseases. Performance of repeated bronchoscopic examinations is not so uncommon. This study was designed prospectively to assess the clinical availability of the Repeated Flexible Bronchoscopy (RFB). METHODS: Pre-established indications were as follows; 1) To confirm diagnosis or the cell type in proven malignancy, 2) For diagnosis or location of hemoptysis, 3) For follow-up or confirming recurrence, 4) For therapeutic purposes. We performed RFB and analysed the data in 156 patients during 28-month period. RESULTS: The frequency of RFB was 23.0%. The indication for diagnosis or cell type of malignancy was 25 cases, in which 2 cases were confirmed by the third bronchoscopic examination and 3 cases by surgical procedures. Localization of bleeding site was confirmed in 53.8%. RFB for small cell lung cancer yielded more information on residual or recurred lesion not apparent even with the CT scan in 30%. Previous cases of bronchostenosis due to endo-bronchial tuberculosis was shown to have worsened in 66.7%. Therapeutic manipulations were done in 126 cases and bronchial suction was most common. Complications showed decreasing tendency with repeated examinations. CONCLUSION: The RFB for diagnosis or cell type of malignancy was useful in that comfirmation of diagnosis was possible in 85.7% of malignancy. More aggressive procedures should be employed including TBLB or TBNA. The RFB showed the possibility of usefulness in the follow-up of patients with small cell lung cancer. For the patients with hemoptysis or endobronchial tuberculosis, the RFB did not showed the significance because its results did not influence the diagnosis, therapy or clinical course.