OBJECTIVE:: This study aimed to assess the attributable risk and potential benefit of smoking cessation on surgical outcomes. SUMMARY BACKGROUND DATA:: Risk reduction with the implementation of surgical care improvement project process measures has been the primary focus for improving surgical outcomes. Little emphasis has been placed on preoperative risk factor recognition and intervention. METHODS:: A retrospective cohort analysis of elective operations from 2002 to 2008 in the Veterans Affairs Surgical Quality Improvement Program for all surgical specialties was performed. Patients were stratified by current, prior, and never smokers. Adjusted risk of complication and death was calculated using multilevel, multivariable logistic regression. RESULTS:: Of 393,794 patients, 135,741 (34.5%) were current, 71,421 (18.1%) prior, and 186,632 (47.4%) never smokers. A total of 6225 pneumonias, 11,431 deep and superficial surgical-site infections, 2040 thromboembolic events, 1338 myocardial infarctions, and 4792 deaths occurred within 30 days of surgery. Compared with both never and prior smokers individually and controlled for patient and procedure risk factors, current smokers had significantly more postoperative pneumonia, surgical-site infection, and deaths (P < 0.001 for all). There was a dose-dependent increase in pulmonary complications based on pack-year exposure with greater than 20 pack years leading to a significant increase in smoking-related surgical complications. CONCLUSIONS:: This is the first study to assess the risk of current versus prior smoking on surgical outcomes. Despite being younger and healthier, current smokers had more adverse perioperative events, particularly respiratory complications. Smoking cessation interventions could potentially reduce the occurrence and costs of adverse perioperative events. Copyright C © 2011 by Lippincott Williams & Wilkins.