The purpose of the study was to determine the clinical utility and practical application of preoperative brain natriuretic peptide (BNP) levels. This is a retrospective review of operating room procedures from November 2006 to March 2009. Preoperative history and physical were reviewed and BNP laboratory levels obtained prior to all procedures and the postoperative course reviewed for incidence of 30-day cardiac complications. A receiver operator curve analysis demonstrated that a preoperative BNP threshold ≥95.5 pg/mL correctly identified 75% of patients with cardiac complications and values ≤18.5 pg/mL identified 100% of patients without adverse postoperative cardiac complications. Multivariable analysis also revealed a history of peripheral arterial disease as the most significant preoperative predictor of cardiac complications followed by BNP above the threshold (odds ratio = 3.7), hypothyroidism, coronary artery disease and prior myocardial infarction. In conclusion, preoperative BNP levels are a useful adjunct in clinical practice to help identify those patients with a high postoperative risk and those with a minimal postoperative risk.