Randomized controlled trials have shown conflicting results regarding the outcome of bivalirudin in primary percutaneous coronary intervention (PPCI). The aim of this study was to evaluate the in-hospital outcomes of patients receiving heparin or bivalirudin in a real-world setting of PPCI: 7,023 consecutive patients enrolled in the Austrian Acute PCI Registry were included between January 2010 and December 2014. Patients were classified according to the peri-interventional anticoagulation regimen receiving heparin (n = 6430) or bivalirudin (n = 593) with or without GpIIb/IIIa inhibitors (GPIs). In-hospital mortality (odds ratio [OR] 1.13, 95% confidence interval [CI] 0.57 to 2.25, p = 0.72), major adverse cardiovascular events (OR 1.18, 95% CI 0.65 to 2.14, p = 0.59), net adverse clinical events (OR 1.01, 95% CI 0.57 to 1.77, p = 0.99), and TIMI non–coronary artery bypass graft-related major bleeding (OR 0.41, 95% CI 0.09 to 1.86, p = 0.25) were not significantly different between the groups. However, we detected potential effect modifications of anticoagulants on mortality by GPIs (OR 0.12, 95% CI 0.01 to 1.07, p = 0.06) and access site (OR 0.25, 95% CI 0.06 to 1.03, p = 0.06) favoring bivalirudin in femoral access. In conclusion, this large real-world cohort of PPCI, heparin-based anticoagulation showed similar results of short-term mortality compared with bivalirudin. We observed a potential effect modification by additional GPI use and access favoring bivalirudin over heparin in femoral, but not radial, access.