BACKGROUND: Blood pressure monitoring and management are critical nursing tasks in patients with aneurysmal subarachnoid haemorrhage (SAH). Yet, it remains unclear to several bedside nurses whether high or low blood pressure is associated with better outcomes. AIM: The aim of this study was to investigate whether blood pressure predicts mortality and hospital length of stay in patients with aneurysmal SAH. STUDY DESIGN: This was a retrospective case-control study of patients who were 18-75 years of age, diagnosed with spontaneous SAH due to aneurysm rupture were included in this study. Patients with debilitating neurological deficit at the time of admission and those with traumatic SAH were excluded. Mortality and length of stay were extracted from the medical records. Cox proportional hazard model and generalized estimating equation were used for the repeated measures of blood pressure. Analyses were adjusted for age, gender, and use of vasopressors. RESULTS: We included 53 patients of which 28% died in the hospital. Higher systolic, diastolic, and mean arterial blood pressure were associated with lower hazard ratios for mortality. Furthermore, higher systolic blood pressure was significantly associated with a longer hospital stay, but no significant associations were observed with diastolic and mean blood pressure. CONCLUSIONS: Moderately elevated blood pressure is associated with lower hazard rate for death. Future studies are required to prospectively investigate the optimal target blood pressure that improves survival after aneurysmal subarachnoid Haemorrhage. RELEVANCE TO CLINICAL PRACTICE: Nurses should develop individualized care plans based on aneurysmal subarachnoid haemorrhage patients' blood pressure readings. For patients with low systolic blood pressure, nurses may need to implement strategies to manage and monitor their condition more closely.