To compare clinical (non-invasive) diagnosis with bronchoscopic (invasive) diagnosis, a total of 50 patients with chronic pneumonia (sputum smear-negative for tuberculosis) were examined. Age range was 12-82 years. Sensitivity of clinical diagnosis was 100% for tuberculosis and 81.8% for lung cancer; specificity was 67.5% for tuberculosis and 89.7% for lung cancer. Clinical diagnosis was correct in 43.4% of cases suspected of tuberculosis and 69.2% of cases suspected of lung cancer. It may be reliable only for elderly women smokers. Because tuberculosis is over-diagnosed in endemic areas, bronchoscopy is strongly recommended for all cases of chronic pneumonia.