Background: Although current clinical guidelines recommend the use of thrombus aspiration (TA) during primary percutaneous coronary intervention (PPCI), previous studies evaluating TA demonstrated contradictory results. The aim of this study was to evaluate long-term clinical outcome after TA in adjunct to PPCI for acute ST-segment myocardial infarction (STEMI), as compared with conventional treatment, with the use of paclitaxel-eluting stents or bare-metal stents. Methods: We analyzed data of the PASSION trial, in which 619 patients with STEMI were randomly assigned to a paclitaxel-eluting stent or a bare-metal stent. TA was performed in 311 patients (50.2%). Clinical endpoints at 2 years were compared between patients who received TA during PPCI with patients who underwent conventional PPCI. The primary outcome of interest was a composite of cardiac death, recurrent myocardial infarction (MI), or target-lesion revascularization (TLR). A propensity score model was made to account for baseline differences that could have affected the probability of performing TA. Results: Complete follow-up was available for 598 patients (96.6%). The cumulative incidence of the combined outcome measure of cardiac death, recurrent MI, or TLR was 40 (13.0%) in the TA group and 41 (13.5%) in the conventional PPCI group (HR 0.96; 95% CI 0.62–1.47; P = 0.84). Also after adjusting for propensity score, no significant difference in event rate was observed between both treatment groups. Conclusions: In this post-hoc analysis of the PASSION trial, TA in adjunct to PPCI did not affect rates of major adverse cardiac events at 2 years follow-up, as compared with conventional PPCI. © 2011 Wiley Periodicals, Inc.