Patients undergoing primary angioplasty in clinical practice experience a higher risk for adverse events than those enrolled in clinical trials. Whether glycoprotein (GP) IIb/IIIa inhibitor use during primary angioplasty is both safe and effective in real life is unknown. Therefore, we examined the pattern of GP IIb/IIIa use and its effectiveness in a large population-based cohort of 7,321 patients who underwent primary angioplasty in New York State. Propensity analysis was used to account for the nonrandomized use of GP IIb/IIIa inhibitors. Overall, 78.5% of patients who underwent primary angioplasty received GP IIb/IIIa inhibitors. In-hospital mortality was significantly lower with GP IIb/IIIa use (3% vs 6.2%, p <0.0001) after adjustment for both propensity score (odds ratio 0.57, 95% confidence interval 0.44 to 0.74, p <0.0001) and the combination of propensity score and clinical characteristics (odds ratio 0.63, 95% confidence interval 0.45 to 0.88, p = 0.006). Patients with older age and higher Mayo Clinic Risk Score (MCRS) received GP IIb/IIIa inhibitors less often. However, stratified analysis of patients with low to moderate risk (MCRS <12) versus high risk (>or=12) demonstrated that GP IIb/IIIa use lowered risk of mortality both in low- to moderate-risk (1.39% vs 3.23%, p <0.0001) and high-risk patients (16.15% vs 22.41%, p = 0.03). In conclusion, adjunct GP IIb/IIIa inhibitor use during primary angioplasty is effective and associated with improved in-hospital survival rates.