Adjunctive blockade of the platelet glycoprotein (GP) IIb/IIIa receptor during either percutaneous coronary intervention (PCI) or for patients who present with non-ST segment elevation acute coronary syndromes has demonstrated efficacy in reducing platelet-mediated adverse cardiovascular ischemic events. The three currently available agents (abciximab, eptifibatide, tirofiban) differ markedly in pharmacodynamic and pharmacokinetic profiles, receptor affinity, and cost. Although pharmacoeconomic substudies are available from placebo-controlled randomized trials of platelet GPIIb/IIIa blockade during PCI, “real-world” cost-effectiveness data from high-volume practice are lacking. Therefore, in-hospital and late (6-month) clinical outcomes and cumulative cost/charge data were analyzed on 1472 consecutive PCI procedures (70% received abciximab) performed by high-volume operators at a single institution. 1 Data were adjusted for lack of randomized treatment allocation with the use of a propensity scoring technique. Adjunctive abciximab therapy for PCI was associated with a significant (3.4%) reduction in mortality to 6 months. Based on the economic cost-effectiveness concept of cost per life year gained relative to standard therapy, 2 , 3 abciximab provided a cost-effective survival advantage in high-volume interventional practice that compares very favorably with currently accepted standards. Clinical and procedural demographics associated with increased cost-effectiveness include multivessel coronary intervention, stent deployment, recent (<1 week) myocardial infarction (MI), and impaired left-ventricular (LV) function. (Am Heart J 2000;140:S148-53.)