Empyema thoracis following pneumonia, intra-abdominal pathology, trauma, and surgical procedure continues to be a source of major morbidity and mortality. Thirty seven adult and eleven pediatric patients with empyema thoracis were treated at the University of Yeungnam Medical Center from May 1983 to November 1986. Age distribution ranged from 6 months to 72 years and showed a double-peaked curve with the highest incidence between 36 and 65 years and below 15 years of age. There were male predominence in patients above 16 years of age. The most common predisposing factors was impaired consciousness due to either alcoholism or head injury. The causes of empyema were as follows: pneumonia 64.6%, lung abscess 6.4%, intraabdominal pathology 6.4%, and surgical procedure 6.4%. The cardinal symptoms were fever, cough, chest pain, dyspnea, sputum, weight loss, anorexia, and night sweat in orders. Culture of empyema fluid were positive in 50% of patients. The isolated organisms were Gram-negative bacilli 33.3%, staphylococcus aureus 25%, and streptococcus 25%. The patients received antibiotics in conjunction with various invasive procedures : chest tube drainage 77.1%, decortication 6.3%, and repeated thoracentesis 10.3%. There were 4 deaths, 1 child and 3 adults, with a overall mortality of 8.3%.