Background: Although elderly patients with thoracic disease were considered to be poor candidates for thoracotomy before, recent advances in preoperative and postoperative care as well as surgical techniques have improved outcomes of thoracotomies in this patient group. The aim of this study was to investigate surgical risk factors and results in elderly patients (aged >= 70 years) with thoracic empyema. Methods: Seventy-one elderly patients with empyema thoracis were enrolled and evaluated from July 2000 to April 2003. The following characteristics and clinical data were analysed: age, sex, aetiology of empyema, comorbid diseases, preoperative conditions, postoperative days of intubation, length of hospital stay after surgery, complications and mortality. Results: Surgical intervention, including total pneumonolysis and evacuation of the pleura empyema cavity, was carried out in all patients. Possible influent risk factors on the outcome were analysed. The sample group included 54 men and 17 women with an average age of 76.8 years. The causes of empyema included parapneumonic effusion (n = 43), lung abscess (n = 8), necrotizing pneumonitis (n = 8), malignancy (n = 5), cirrhosis (n = 2), oesophageal perforation (n = 2), post-traumatic empyema (n = 2) and post-thoracotomy complication (n = 1). The 30-day mortality rate was 11.3% and the in-hospital mortality rate was 18.3% (13 of 71). Mean follow up was 9.4 months and mean duration of postoperative hospitalization was 35.8 days. Analysis of risk factors showed that patients with necrotizing pneumonitis or abscess had the highest mortality rate (10 of 18, 62.6%). The second highest risk factor was preoperative intubation or ventilator-dependency (8 of 18, 44.4%). Conclusion: This study presents the clinical features and outcomes of 71 elderly patients with empyema thoracis who underwent surgical treatment. The 30-day surgical mortality rate was 11.3%. Significant risk factors in elderly patients with empyema thoracis were necrotizing pneumonitis, abscess and preoperative intubation/ventilation. This study also suggested that surgical treatment of empyema thoracic in elderly patients is recommended after failed conservative treatment because of the acceptably postoperative complication and mortality rate.