A walk through any intensive care unit in the world will quickly reveal that although we have made significant strides in the management of subarachnoid hemorrhage, we still have a long way to go. As practitioners, the status quo will never be good enough. The principal challenge, we face in caring for patients after successful endovascular or microsurgical treatment of their culprit lesions is the disheartening devastation caused by delayed cerebral ischemia. It is written by clinicians, for clinicians to provide real-world information based on our current understanding of the disorder with the hope that it will lay the foundation for optimizing treatments across the world. With that goal in mind, we embark upon this journey with you.