This chapter presents a case study of a 62-year-old female presented to the operating room with a diagnosis of two large intracranial aneurysms. The case is a discussion of the application of deep hypothermic circulatory arrest (DHCA) for patients undergoing large and/or complex intracranial aneurysm clipping and repair. The patient was brought to the operating room, noninvasive monitors placed, and under local anesthesia a right radial arterial line was established. The rationale behind the technique of DHCA stems from the significant advantage the surgeon has once blood flow has stopped circulating to the aneurysm. The margin for error is small, and success depends upon an experienced and knowledgeable team. The safe practice and management of DHCA requires an extensive understanding of cardiac and neurosurgical anesthetic practice, cardiopulmonary bypass (CPB), as well as careful consideration and proper planning.