Aim: To evaluate the utility of fiberoptic bronchoscopy in order to find out the etiology in various lung conditions. Materials and Methods: Fiberoptic bronchoscopy was performed in 120 adult patients who had persistent opacities on chest radiography in the form of collapse, consolidation, hilar mass and cavity with proper antibiotic course of 1 to 3 months. Bronchoscopic aspirates, brushing and biopsy (as and when required) were taken. Patient with known lung cancer, sputum positive pulmonary TB, recent myocardial infarction, allergic diseases and blood dyscrasias were excluded. Results: Fiberoptic bronchoscopy was diagnostic in 90 (75%) patients. Bacterial pneumonias were found in 32 (26.66%), malignancy in 28(23.33%), pulmonary TB in 20 (16.66%), fungal pneumonia in 6(5%) and foreign bodies in 4(3.33%) patients. In 30(25%) patients no specific diagnosis was made. Conclusion: We conclude that fiberoptic bronchoscopy was found to be extremely useful in finding specific etiology of various lung diseases.