Background: A systematic bias leading to the underreporting of carotid endarterectomy (CEA) complications has been suggested in published reports. The possibility of an evidence-practice gap in conjunction with uncertainties regarding operator and institutional performance impede clinical decisions by practitioners for carotid revascularization. Methods: A prospective, independent monitoring system was implemented alongside an ongoing retrospective, self-reported quality assurance (QA) system for CEA at a major metropolitan tertiary care academic medical center. Independent, trained monitors from the neurology department examined all patients undergoing CEA both preoperatively and postoperatively at 24 hours and 30 days. Data was collected on patient demographics, medical history, and procedural and anatomical variables. Outcome data from the independent QA system was compared against self-reported data for the same cohort of patients, excluding CEA performed concurrently with another procedure (typically cardiac surgeries) or non-vascular surgeons. Results: From July 2008 through June 2010 vascular surgeons performed 462 isolated CEA at the institution. Stroke and death was detected at greater frequency by the independent QA system than was self-reported by the surgical staff (3.7% versus 1.7%, p=0.05). Self-reported outcomes from the study cohort matched those previously published in a peer-reviewed journal using the same self-reporting system (1.7% versus 1.4%, p=0.52). Conclusions: In the same cohort of patients, the reported periprocedural stroke and death rate for CEA is higher comparing prospective, independent, trained monitors to surgeon self-reporting. As public health policy mandates rigorous assessment of outcome, and ultimately, performance-based reimbursement, the validity of QA systems merits heightened attention.