Patients with an aneurysmal subarachnoid haemorrhage (SAH) frequently require admission to the intensive care unit. There, a variety of therapeutic strategies are initiated, in addition to definitive procedures aimed at securing the aneurysm. Despite a substantial investment in caring for these patients, outcomes for this group remain poor. Although the severity of the initial bleed is crucial in this context, many patients undergo further deterioration in the ICU. Delayed cerebral ischaemia is a significant cause of longterm morbidity and mortality after SAH. There are limited data supporting much of the critical care provided to patients with SAH in the ICU, leading to substantial institutional and practitioner variation in treatment. Whether this influences patient outcomes is unknown, although it represents a major knowledge gap in neurocritical practice in Australia and New Zealand.