Elective peripheral circulatory arrest under moderate hypothermia in neurosurgical operations on intracranial aneurysms and angiomata gives improved operating conditions and a lower mortality and morbidity than previous methods. Circulatory arrest can be achieved by means of intracardiac pacing and placement of a balloon catheter in the ascending aorta, at the same time allowing adequate coronary artery perfusion. The management and complications in a series of thirty-seven consecutive cases are described and discussed.