With the advent of multiple potent antiplatelet and anticoagulation agents in percutaneous coronary intervention (PCI), the risk of bleeding complications has increased. The optimal dose of unfractionated heparin in this setting is unclear. This study was designed to determine the feasibility and safety of PCI with an ultra-low-dose weight-adjusted unfractionated heparin regimen (30 IU/kg bolus, maximum 3,000 IU) in combination with aspirin, clopidogrel, and eptifibatide. We enrolled 83 patients who underwent nonemergency PCI of native coronary arteries. At 30 days, all patients were free of the primary clinical outcomes defined as a composite of death, myocardial infarction, or repeat target vessel revascularization, and there were no major bleeding complications.