A 52-year-old woman developed aortitis syndrome in addition to polycythemia vera. Angiographic examination following the patient's complaint of inflammatory pain in the right 5th toe and intermittent claudication of the lower limbs showed obstructive lesions in the abdominal aorta and iliac arteries. During the operation (aortobifemoral synthetic bypass installment), much bleeding was observed. This hemorrhagic tendency continued until the 4th day after operation. Acute deep venous thrombosis and hemorrhagic gastric ulcer appeared on the 17th and 21st day, respectively. Consequently, treatment with anticoagulants and fibrinolytic agents was discontinued. Both complications, however, abated with conservative treatment, and the clinical course was uneventful. Histopathological examination revealed “aortitis”. The questions involved in the combined case of polycythemia vera and aortitis syndrome are (1) how the hemorrhagic-coagulation system is affected by arterial reconstructive surgery and (2) what countermeasures should then be taken.