The aim of this study was to assess whether delayed resuscitation bundle compliance from 6 to 12 h after a diagnosis of septic shock has an impact upon 28-day mortality. A prospective observational study on consecutive adult patients with septic shock was performed in the Emergency Department (ED) of a tertiary care university-affiliated hospital between January 2010 and July 2012. Compliance with the resuscitation bundle was assessed at 6 and 12 h after a septic shock diagnosis (time 0). Patients were divided into three groups: early compliance (≤6 h), delayed compliance (>6 but ≤12 h), and non-compliance (>12 h). The 28-day mortality was compared among the groups. A total of 332 patients were included, with an overall 28-day mortality of 17.2%. The mean age was 63.9 years; 57.8% were men. Early compliance was achieved in 195 patients (58.7%), delayed compliance in 59 patients (19.8%), and non-compliance in 78 patients (23.5%). The groups did not differ in baseline sequential organ failure assessment illness severity. However, the non-compliance group had a significantly higher mortality (29.5%) than the delayed-compliance (13.6%) and early-compliance (13.3%) groups (p = 0.04). Delayed compliance was associated with a lower mortality risk than non-compliance (adjusted odds ratio 0.32, 95% confidence interval: 0.13-0.82, p = 0.02). In conclusion, if bundle therapy be started at the time of presentation, the outcome of delayed resuscitation bundle compliance within 12 h is same as that of early resuscitation bundle compliance within 6 h, and these are better than that of the patients who had late or no compliance.