For the past 5 year 6 months from January 1975 to June 1980, 176 patients with empyema have been treated in Chonnam University Hospital. They were 134 males and 42 females ranging from ] 8 days to 69 years of age. [mean age: 26.1 years] The duration of illness prior to treatment was relatively shorter in pediatric group than in adult group, that is, the duration of less than 1 month was 89.5% in pediatric group and 38.0% in adult group. In bacteria study there were Staphylococcus 26.1%, Streptococcus 17.6%, E. coil 10.8%, Pseudomonas 10.8%, Diplococcus pneumoniae 5.7% and Candidia. And 4 children and 3 adults had infections of two species of bacteria. The underlying pathologic lesions were pyogenic pneumonia 34.7%, tuberculosis 29.5%, paragonimiasis 15.3%, trauma 9.7% and postoperative state. The over-all mortality rate was 1.7% [3 patients]. The causes of death were sepsis In 1 child and sepsis secondary to esophageal fistula in 2 adults. Adequate drainage and obliteration of the pleural space seems to be the most important aspect of treatment and can frequently be achieved by initial tube drainage in acute empyema, especially in the pediatric group. The chronic thick walled or loculated cavities required open window therapy, decortication, resection therapy and sterilization. Modified Eloesser`s operation and 0.3-0.5% potadine irrigation brought good result in the patients who had general weakness, marked pulmonary parenchymal destruction due to pyothorax, and pyothorax with severe bronchopleural fistula.