Background: Endovascular coiling (EVC) has been shown to yield superior clinical outcomes to surgical clipping (SC) in the treatment of ruptured cerebral aneurysms. The reasons for these differences remain obscure. We aimed to assess outcomes of EVC and SC relative to baseline physiological derangement. Methods: This was an exploratory analysis of prospectively collected trial data. Physiological derangement was assessed using the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system. Other contributory variables such as age, World Federation of Neurosurgical Societies (WFNS) grade, and development of complications, including hydrocephalus and vasospasm, were included in the analysis. Clinical outcome was independently assessed at 90 days using the modified Rankin Scale (MRS). Hospital stay, ventilated days, and total norepinephrine dose were also used as secondary outcomes. Multivariate analysis was performed using binary logistic regression. Results: EVC was performed in 69 patients and SC in 66 patients. More profound physiological derangement (APACHE II score >15) was the strongest predictor of poor outcome in the overall cohort (OR 17.80, 95% CI 4.78 to 66.21, p<0.0001). For those with more deranged physiology (APACHE II score>15; 59 patients), WFNS grade ≥4 (OR 6.74, 1.43 to 31.75) and SC (OR 6.33, 1.27 to 31.38) were significant predictors of poor outcome ( p<0.05). Favorable outcome (MRS 0-2) was seen in 11% of SC patients compared with 38% of EVC patients in this subgroup. SC patients had significantly increased total norepinephrine dose, ventilated days, and hospital stay ( p<0.05). Conclusions: More profound physiological derangement at baseline is a strong predictor of eventual poor outcome, and outcomes for patients with more profound baseline physiological derangement may be improved if undergoing a coiling procedure.