Aortic valve replacement (AVR) in the presence of a calcified aorta or patent grafts may preclude clamping of the ascending aorta. We employed deep hypothermic circulatory arrest in order to circumvent this problem.Between January 1993 and December 2000, 415 patients underwent AVR in our department. Eight of these were operated using deep hypothermic circulatory arrest. There were 5 males, and mean age was 72 years (range 56-81). Indications for using circulatory arrest were reoperation with patent grafts and/or severe calcification of the ascending aorta. In six patients, cardiopulmonary bypass was achieved via femoro-femoral bypass, and in two via aortic-right atrial cannulation. Retrograde cerebral perfusion was employed in five. Mean bypass time was 155 minutes (range 122-187), and mean circulatory arrest time was 38 minutes (range 31-49).There was no operative mortality, and no patient suffered any neurologic sequelae. Echocardiography showed all valves to be functioning well.AVR under deep hypothermic circulatory arrest can be accomplished with an acceptable degree of safety. It should be considered as an alternative in patients in whom aortic clamping is prohibitive, and might otherwise be considered inoperable. The ability to connect the patient to bypass and the presence of a "window" to allow aortotomy are prerequisites for employing this method.