['Although chronic obstructive pulmonary disease (COPD) has been implicated as a risk factor for abdominal aortic aneurysm (AAA) rupture, its effect on surgical repair is less defined. Consequently, variation in practice persists regarding patient selection and surgical management. The purpose of this study was to analyze the effect of COPD on patients undergoing AAA repair.', 'We reviewed a prospective regional registry of 3455 patients undergoing elective open AAA repair (OAR) and endovascular AAA repair (EVAR) from 23 centers in the Vascular Study Group of New England from 2003 to 2011. COPD was categorized as none, medical (medically treated but not oxygen [O2]-dependent), and O2-dependent. End points included in-hospital death, pulmonary complications, major postoperative adverse events (MAEs), extubation in the operating room, and 5-year survival. Survival was determined using life-table analysis based on the Social Security Death Index. Predictors of in-hospital and long-term mortality were determined by multivariate logistic regression and Cox proportional hazards analysis.', 'During the study interval, 2043 patients underwent EVAR and 1412 patients underwent OAR with a nearly equal prevalence of COPD (35% EVAR vs 36% OAR). O2-dependent COPD (4%) was associated with significantly increased in-hospital mortality, pulmonary complications, and MAE and was also associated with significantly decreased extubation in the operating room among patients undergoing both EVAR and OAR. Five-year survival was significantly diminished among all patients undergoing AAA repair with COPD (none, 78%; medical, 72%; O2-dependent, 42%; P\xa0<\xa0.001). By multivariate analysis, O2-dependent COPD was independently associated with in-hospital mortality (odds ratio 2.02, 95% confidence interval, 1.0-4.0; P\xa0= .04) and diminished 5-year survival (hazard ratio, 3.02; 95% confidence interval, 2.2-4.1; P\xa0< .001).'] Is severity of chronic obstructive pulmonary disease associated with adverse outcomes in patients undergoing elective abdominal aortic aneurysm repair?