In addition to efficacy and safety, cost is an important determinant of the use of glycoprotein IIb/IIIa (GPIIb/IIIa) therapy in patients with acute coronary syndromes (ACS) or undergoing percutaneous coronary intervention (PCI). In PCI, the average procurement cost of GPIIb/IIIa therapy ranges from $US400 to $US1500 (1999 values) per patient treated, depending on agent, dose and duration of infusion. Prospective economic substudies with abciximab and tirofiban have demonstrated subsequent cost savings that partially offset the procurement costs of the agents. The drug procurement costs per death or myocardial infarction (MI) prevented in PCI appear to vary from $US10 500 to $US37 000, depending on the agent. Abciximab has been proven to provide a survival benefit in the setting of PCI, including coronary stenting. Analyses of abciximab use yield cost-effectiveness ratios of $US2875 to $US14 765 per life-year or quality-adjusted life-year saved, which compares favourably with most widely accepted therapies. In non-ST-segment elevation ACS, drag procurement costs range from $US700 to $US1700 per patient treated, also depending on agent, dose and duration of infusion. Evidence of cost offsets from changes in subsequent resource utilisation are limited and seem contingent upon a conservative risk-stratification approach. Drug procurement costs have been calculated as $US32 000 to $US82 000 per death or MI prevented in the ACS trials. Cost-effectiveness ratios of $US16 000 per life-year saved for the US and Western European cohorts in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial are favourable. If these analyses prove correct, the cost effectiveness of GPIIb/IIIa receptor therapy for patients with non-ST-segment elevation ACS will also compare favourably with other widely accepted therapies in industrialised countries. More clinical and economic data are necessary to allow better selection of specific patients who will receive the most benefit from GPIIb/IIIa therapy in healthcare systems with limited resources.