It is well known that radiological study is the most important and mandatory procedure to establish the presence of bronchiectasis and to determine precise extent. In every individual case, the diagnosis is established by, and the indication for surgery is based on, the detailed radioligical findings. During four years from September, 1972 to September, 1976, clinical and radiologic findings of 100 cases of proven bronchiectasis with no acid fast bacillus in sputum at Seoul National University Hospital are analysed. The diagnosis was based on bronchography in all cases. The results are as follows: 1. The relation of male to female was 6:4 and peak incidence was in third decade. 2. Chronic cough, purulent sputum and hemoptysis were main symptoms. 3. Moist rales and wheezing, heared over the affected area of the lung, were main clinical signs but no physical findings was found in 41% of cases. 4. Simple chest P-A films revealed various findings indicating bronchiectasis and were highly suggestive of bronchiectasis in the great majority of cases but were normal in 8% of cases. 5. The extent of the disease was usually confined to one or two lobes and the left lung was much more often involved than the right. Bilateral involvement was approximately 30% incidence. The involvement was the left lower lobe, the lingular segment of the left upper lobe, and the right lower lobe in order of frequency.