Objective: To evaluate the association between time from ED presentation to intensive care unit (ICU) transfer on mortality in patients presenting with septic shock. Methods: Adult patients with suspected septic shock enrolled in the Australasian Resuscitation in Sepsis Evaluation trial were included. The primary outcome of this post-hoc analysis was 90-day mortality. ED-to-ICU time was analysed as both a continuous variable and a binary variable (≤ vs >4 h). Analysis incorporated mixed effects regression, with ICU site as a random effect, time-to-event analysis and competing risks regression; all with and without inverse probability of treatment weighting to account for confounding baseline covariates. Results: Data from 1301 patients were included. Median (interquartile range [IQR]) ED-to-ICU time was 4.3 (3.1, 6.3) hours, with 588 patients (45%) transferred within 4 h. The ≤4-h group were younger, 64 (51, 74) versus 67 (52, 76) years (P = 0.04), with higher APACHE III scores, 50 (37, 65) versus 47 (35, 62) (P = 0.002), and higher unadjusted 90-day mortality, odds ratio (OR) 1.53 (95% confidence interval 1.15, 2.03), P = 0.01. After adjustment for pre-specified confounders, the 90-day mortality OR was 1.09 (0.83, 1.44), P = 0.52. Adjusted for death as a competing event and illness severity, hospital length of stay was similar between groups, whereas ICU duration remained longer for the ≤4-h group. Conclusion: In patients presenting to the ED with septic shock, ED-to-ICU time less than 4 h was not associated with altered 90-day mortality, although this should be interpreted with caution due to study limitations.