To evaluate the clinical significance of lung ventilation scan using ""Tc-DTPA in patient with bronchiectasis, we cornpared the involovement area of bronchogram and lung ventilation scan according to lobar and segmental distribution. There were no correlation between impairment of pulmonary function test and the number of branchiectatic lobe and segment(p>O. 5). Lung ventilation scan showed 66.7% of sensivity, 100% of specificity, and 91.7g of accuracy according to lobar distribution, and 51.9 of sensivity, 96.9% of specificity, and 88.9% of accuracy according to segmental distribution. These results suggest that lung ventilation scan can be used as diagnostic tool in patient with bronchiectasis in whom broncbogram is not tolerable.