We sought to evaluate the effectiveness of using an intra-aortic filtration system for the prevention of particulate emboli transport and the minimization of significant postoperative complications associated with particulate emboli. Between October of 2000 and October 2001, a total of 146 patients were enrolled at Advocate Christ Medical Center as part of the multi-institutional randomized trial (1289 patients at 22 centers). A total of 74 patients (51%) received the Embol-X intra-aortic filter and 72 patients (49%) were enrolled in the control group. Patients were evaluated for neurological deficit, myocardial infarction, renal insufficiency/failure, limb ischemia, and death at 12-hour, 24-hour, 72-hour, 7-day, and 30-day postoperative intervals. All filters received histological examination for particulate matter. Particulate matter was isolated in 70 (94.5%) of the filters successfully deployed. There was no statistically significant difference in the device related events between the filter and conventional cannulation groups (9/74 = 12.1% vs. 7/72 = 9.7%). Although not clinically evident, the primary event for both groups was ascending aortic intimal tears. There was one death in each of the groups not related to the filter or cannula used. The use of the Embol-X intra-aortic filter system has proven to be a safe and effective means to reduce the introduction of particulate emboli into the systemic circulation. Clearly, the reduction of particulate matter by as much as 95% justifies its use in cardiac surgery patients identified with an increased pre-operative embolic risk.