Glycoprotein IIb/IIIa inhibitors are used as an adjunct to antiplatelet therapy in percutaneous coronary intervention to reduce postprocedural enzyme elevations. Previous studies have shown a risk for thrombocytopenia that is associated with these agents. We sought to evaluate the incidence and outcomes of glycoprotein IIb/IIIa inhibitor-associated thrombocytopenia in an unselected series of patients undergoing percutaneous coronary intervention. We reviewed 984 interventions performed on 908 subjects over a specific time period. Glycoprotein IIb/IIIa inhibitors were used in 58.8% of cases. Their use increased from 38 to 82% during the study period (p < 0.0001). The incidence of glycoprotein IIb/IIIa inhibitor-associated thrombocytopenia was 5.4%. The occurrence of thrombocytopenia was not associated with higher age, gender or ethnicity. The preprocedural platelet count was not associated with induced thrombocytopenia (237 ± 76 vs. 209 ± 68 × 10<sup>3</sup>, p > 0.05). The occurrence of thrombocytopenia was not associated with increased in-hospital mortality, 1-year mortality, myocardial infarction or revascularization, but was associated with a hospital stay twice as long as in those patients without thrombocytopenia (5.6 ± 11.3 vs. 2.1 ± 2.2 days, p < 0.001). Of the 5.4% of patients who developed thrombocytopenia, only 2 patients (7.1%) required platelet or blood cell transfusion.