With increased collaboration between surgeons and industry, there has been a push towards improving transparency of conflicts of interest (COIs). This study aims to determine the accuracy of reporting of COIs among studies in major vascular surgery journals. A literature search identified all comparative studies published from January 2018 through December 2018 from three major United States vascular surgery journals (Journal of Vascular Surgery, Vascular and Endovascular Surgery, and Annals of Vascular Surgery). Industry payments were collected using the Centers for Medicare and Medicaid Services Open Payments database. COI discrepancies were identified by comparing author declaration statements with payments found for the year of publication and year prior. A total of 239 studies (1642 authors) were identified. Two hundred twenty-one studies (92%) and 669 authors (63%) received undisclosed payments when utilizing a cut-off payment amount of $250. In 2018, 10,778 payments (totaling $22,174,578) were made by 145 companies. Food and beverage payments were the most commonly reported transaction (42%), but accounted for only 3% of total reported monetary values. Authors who accurately disclosed payments received significantly higher median general payments compared with authors who did not accurately disclose payments ($56,581 interquartile range, $2441-$100,551 vs $2361 interquartile range, $525-$9,699; P < .001). When stratifying by dollar-amount discrepancy, the proportions of authors receiving undisclosed payments decreased with increasing payment thresholds. Multivariate analysis demonstrated that first and senior authors were both significantly more likely to have undisclosed payments (odds ratio, 2.0; 95% confidence interval, 1.1-3.6 and odds ratio, 2.9; 95% confidence interval, 1.6-5.2, respectively). There is a significant discordance between self-reported COI in vascular surgery studies compared with payments received in the Centers for Medicare and Medicaid Services Open Payments database. This study highlights the need for increased efforts to both improve definitions of what constitutes a relevant COI and encourage a standardized reporting process for vascular surgery studies.