We report a case of 67-year-old woman with severe aortic stenosis complicated by polycythemia vera (PV). She has been treated for PV with busulfan over the past three years. On admission, she had increase in white blood cell, red blood cell and platelet count. The pressure gradient between left ventricle and aorta was 170 mmHg. Aortic valve was bicuspid and replaced with a 21 mm Carpentier-Edwards pericardial xenoprosthesis. Ascending aorta with a diameter 6.0 cm was replaced simultaneously with a 30 mm Dacron graft (Hemashield). Post-CPB course was uneventful except for a tendency to the prolongation of activated clotting time. She was discharged from the hospital in good condition.