Background: Risk factors for surgical site infections (SSIs) are well studied after cardiac surgery but there is few data about epidemiology of these infections after non cardiac thoracic surgery. We aimed to investigate epidemiology, risk factors and outcome of postoperative SSIs following thoracic surgery. Methods: All of the patients who undergone thoracic surgical procedure, between 2004 and 2012 were surveyed prospectively for the presence of SSI. Risk factors for SSIs after open thoracic surgery were analysed with a case-control study: 80 patients with SSIs were compared with 96 patients who were operated during the study period but did not develop SSI. Results: A total of 100 surgical site infections diagnosed in 4572 patients (2.18%). Open surgery was associated with SSIs more frequently than thoracoscopic surgery (P<0.001). Risk adjusted rates for open thoracic SSI were available between 2009 to 2012 and 1.91%, 3.59% and 7.69% for risk index category 0, 1 and 2-3 respectively. Staphylococus aureus (25%), coagulase-negative staphylococci (18%) and (17%) were the most frequently isolated microorganisms. Diabetes mellitus (DM), an American Society of Anestesiology (ASA) score >= 3, preoperative white blood cell (WBC) count and the number of blood products used perioperatively were found to be independent risk factors for SSIs. Mortality rate and total length of hospital stay were significantly higher in patients with SSIs. Conclusion: Higher WBC count before surgery could indicate higher risk of SSI after thoracic surgery. Decreasing blood and blood product use perioperatively could lower the rate of SSIs.