Surgical management of giant and complex posterior circulation aneurysms continues to be a technically difficult task with high operative morbidity. To minimize morbidity we have used cardiopulmonary bypass and circulatory arrest for the treatment of a giant basilar aneurysm. A 48-year-old woman presented with sudden headache. Magnetic resonance angiography revealed a giant basilar aneurysm. On the 2nd hospital day she developed right sided hemiparesis and cranial nerve deficits as a result of the second rupture of the aneurysm. The aneurysm was successfully treated and no significant neurological complications were related to this technique. This initial experience indicates that patients with giant posterior circulation aneurysm that cannot be treated using conventional techniques might benefit from a surgical approach that included the use of deep hypothermic circulatory arrest.