Vascular surgery is considered a higher risk surgical specialty, as many patients undergoing vascular procedures are elderly and have other comorbid illnesses, putting them at elevated risk of postoperative complications. This study used Patient Safety Indicators (PSIs) to analyze more than 1.4 million patients who underwent vascular surgery from 2005–2009 and found that more than 5% experienced a postoperative adverse event. Procedural complexity and comorbidities were associated with increased risk of a PSI, corroborating prior studies that have found a link between illness severity and risk of complications in medical patients. The PSIs are best used to screen administrative data for potential adverse events, as in this study. In surgical patients, the National Surgical Quality Improvement Program measures have been shown to be superior for accurate detection of postoperative adverse events.