Postoperative bleeding is a common complication following cardiothoracic surgical procedures requiring cardiopulmonary bypass (CPB). Serious bleeding complications requiring the administration of blood products, hemostatic drugs, and even repeat surgery are associated with considerable morbidity, mortality, and resource consumption. Therapy with recombinant activated factor VII (rFVIIa) may be an effective treatment strategy for patients with refractory bleeding. We report the successful use of rFVIIa for the treatment of intractable postoperative bleeding following aortic aneurysm repair in two patients with Marfan syndrome. In both patients, surgical reexploration was avoided, and the patients' clinical status was stabilized after the administration of rFVIIa. In one patient, hemostasis was rapidly achieved within minutes, whereas hemostasis occurred gradually over several hours in the second patient. Including our personal experience with the two cases, the use of rFVIIa has been reported in 20 patients who required CPB for cardiothoracic surgical procedures. Hemostasis was achieved in all patients. In 14 patients (70%), rapid hemostasis was achieved following a single dose of rFVIIa (mean dose, 57 microg/kg). In the remaining six patients, gradual hemostasis was achieved after a mean of 3.4 doses (mean cumulative dose, 225 microg/kg). Two patients (10%) were believed to have experienced thromboembolic complications after the administration of rFVIIa (one was fatal), and, in another patient, intracoronary thrombosis was suspected but was not confirmed. In patients experiencing postoperative bleeding complications that are refractory to treatment with blood products, hemostatic agents, and/or repeat surgery, the use of rFVIIa may be considered.