The author made a clinical study of IIO cases of empyema thoracis who were diagnosed and treated at department of chest surgery, chosun university hospital, during the period of December 1979 through June 1983. 1. In age and sex distribution, 45 cases [41%] was under the age of 15 years, 65 cases [59%] was above the age of 15 years. The ratio of male to female was 2.6:1. 2. The predisposing factors were pneumonia 45 cases [41%] and pulmonary tuberculosis 40 cases [36.5%]. 3. The cardinal symptoms were dyspnea, chest pain, fever, cough in order. 4. Etiologic organisms were confirmed in 69% which requested in 87 cases. Staphylococcal infection were 19 cases, Streptococcal infection were 13 cases, pneumococcal infection were 11 cases. 5. In treatment of empyema, thoracentesis 4 cases, closed thoracotomy 50 cases, open drainage 29 cases, decortication 14 cases and thoracoplasty 13 cases. In children, only thoracentesis and closed thoracotomy was favorable result in treatment. 6. 103 cases were discharged with recovery and improvement but 7 cases were early discharged by their economic or personal condition without improved. [KTCS 1983;4:533-538]