Factor XI deficiency is a very rare congenital coagulation disorder. Bleeding complications should be considered when treating a patient with unstable angina and congenital coagulation disorder during and after percutaneous coronary intervention (PCI). Thrombotic complications can develop after fresh frozen plasma (FFP) transfusion and drug-eluting stent (DES) implantation. We report here on the successful management of a patient having unstable angina with factor XI deficiency, and this patient was treated with PCI under intravascular guidance and with the aid of FFP and hemostatic devices.