Pneumonia is a common postoperative complication, with a mortality of up to 40%. The Post-operative Pneumonia Risk Index (PPRI) was derived from a large cohort of general surgical patients but has not been validated in patients undergoing open abdominal aortic aneurysm (AAA) repair. The PPRI was applied to patients undergoing elective open AAA repair in a tertiary referral vascular unit. Pneumonia occurred in 20% of patients. Receiver operating characteristic curve analysis identified 36 as the optimum PPRI cutoff value. At this cutoff, the likelihood ratio for pneumonia was 1.35 (95% confidence interval 1.08-1.62). However, in a multivariate analysis, only weight loss in excess of 10% over the preceding 6 months was an independent predictor of postoperative pneumonia. Although the PPRI is of some value in identifying high-risk patients undergoing AAA repair, weight loss alone may be predictive, allowing targeted preventive measures in aneurysm patients at increased risk.