Context: The empyema, defined as a collection of pus in the pleural cavity, may be caused as a result of primary complication of cervical or odontogenic infections and can spread to the mediastinum through cervical spaces. Aim: The results of surgical treatment in the patients with empyema were compared. Materials and Methods: The patients suffering from empyema with odontogenic and post-pneumonia infections, treated surgically in 2001-2009, were studied. Twelve patients of odontogenic empyema (Group 1), and 160 patients with post-pneumonia empyema infections (Group 2) were included in this study. Two groups were compared according to the treatments of empyema. Data were extracted from the medical records of the patients which include age, gender, type of treatment, cure rate, mortality rate, hospital stay, and complications. Statistical analysis: independent samples T test, Mann-Whitney U test and, Chi – square or Fisher Exact test were used. Results: The treatment of Group 1 was carried out through cervical, mediastinal and decortication approaches with cure rate of 75% and mortality rate of 25%. 36 patients of Group 2 were treated with minor surgical procedures. The remaining ones were treated surgically with a total cure rate of 90.8% and mortality rate of 1.8%. There were statistically significant differences on event rates of cure rate, mortality, and hospital stay times between two Groups (p= 0.001, p=0.001, p<0.001), however, there were no differences on postoperative complication rates of prolonged air leakages and wound infections (p=0.715, p=0.057). Conclusion: Due to high mortality and low cure rates of odontogenic empyema, early diagnosis and ample cervicotomy with mediastinal drainage are needed, and hence, thoracotomy-decortication may significantly reduce the mortality rate.