Purpose Ruptured AAA (rAAA) requires surgeons to make rapid and complex decisions on whether or not to operate. The Harbourview Risk Score (HRS) shows promise in calculating 30-day mortality. It scores 1 point for age (>76 y), pH (<7.2), SBP (<70mmHg), and Cr (>176.8µmol/L) up to a max of 4. The aim of this study is to validate the HRS locally. The secondary aims were to assess outcomes between open (OR) and endovascular (EVAR) intervention for rAAA. Methodology A multi-centre retrospective review was performed on patients who presented to hospital with a rAAA between 2018 and 2023. Demographic, comorbidity, clinical, and biochemical data was collected. Analyses was carried out using SPSS and Prism. Results 256 patients were included (30% female, mean 75.9 years), of whom 52 (20%) underwent EVAR, 145 (57%) underwent OR, and 59 (23%) non-operatively. 30-day mortality was 17.3% in EVAR and 46.2% in OR (OR 4.1, CI 1.9-9, p<0.001). The operative group comprised of 22.3% females and the palliative group was 54.2% female. Predicted mortality by HRS was 0%, 8%, 35%, 67% for scores 0-3. No patients with a HRS 4 were provided intervention. The HRS score was a better predictor of mortality in patients undergoing EVAR with an AUC of 0.833 compared to open. There was a 2.4-fold increase in 30-day mortality with each increase in HRS point (OR 2.4, CI 1.68-3.56, p<0.001). Conclusion HRS was retrospectively validated in our multi-centre New Zealand study. It is a rapidly calculated score to risk stratify patients and can be considered as a useful adjunct for decision making. Given an improved short to mid-term survival in our setting, where possible, EVAR first strategies should be strongly considered. Long-term data is awaited.