Prior to availability of antibiotics, lung abscess has been recognized as one of the most serious pulmonary disease, and despite of diminished morbidity and mortality rate with the advent of antibiotics and development of better technique in the fields of surgery on pulmonary disease it continues to be a virulent form of pulmonary supuration. It is the purpose of this paper to present a clinical review of 115 lung abscess treated by surgically at "The National Medical Center" during past 9 years. 1. The most common age of occurrence is between the age of 30 and 50, and 105 cases were male and 31 cases occurred in female. 2. Numerous etiological factors may play a role in the formation of a pulmonary abscess; aspiration in 36 patients of which 2 patients had diabetes, 54 patients had preceding URI or pneumonia, and 5 patients followed liver abscess, one of which in hematogenous route. In 20 patients, no predisposing factor could be determined- 3. Clubbing digits were presented in 26 of 1315 patients suggesting chronicity of the disease, and gastric ulcer were combined in 3 of 136 patints. 4. Apparently the onset was insidious, and the progress was masked by indiscriminate administration of antibiotics for URI and TB remedies under impression of pul. tbc. Previous TB treatments were done in 56.%[76 cases] for one week to two years and administration of antibiotics in 51 cases. 5. 89 cases were on tbe right and 2t5 cascs were on the left side. 51 cases of pneumonectomy and 8 of open drainage, of which 4 of Monaldi procedure, were made and operative mortality rate was 5.2%. Numerous complications such as 8 of empyema, 4 of each bleeding and atelectasis, 2 of BPF, 1 of esophageal fistula and one of pneumothorax which were responded well to prolonged treatment with good results, were obtained. 6. The incidence of Klebsiella and Pseudomonas were increased recently. In these results, we submit the surgery should be performed if the conservative therapy had failed. The resection was most favorable operation for pulmonary abscess though drainage procedure may be of value in certain patients with grave systemic menifestations. In chronic long standing abscess, more complications and high mortality rate were assumable although the prognosis has been improved with the advent of antibiotics, the development of improved surgical technique and complete preoperative care.[KTCS 1969;1:3-12]