Traumatic disruption of the pelvic ring has a high risk of mortality. These injuries are predominantly due to high-energy, blunt trauma and severe associated injuries are prevalent, increasing management complexity. This population-based study investigated predictors of mortality following severe pelvic ring fractures managed in an organised trauma system. Cases aged greater than 15 years from 1st July 2001 to 30th June 2008 were extracted from the population-based state-wide Victorian State Trauma Registry for analysis. Patient demographic, pre-hospital and admission characteristics were considered as potential predictors of mortality. Multivariate logistic regression was used to identify predictors of mortality with adjusted odds ratios (AOR) and 95% confidence intervals (CI) calculated. There were 348 cases over the 8-year period. The mortality rate was 19%. Patients aged greater than 65 years were at higher odds of mortality (AOR 7.6, 95% CI: 2.8, 20.4) than patients aged 15–34 years. Patients hypotensive at the scene (AOR 5.5, 95% CI: 2.3, 13.2), and on arrival at the definitive hospital of care (AOR 3.7, 955 CI: 1.7, 8.0), were more likely to die than patients without hypotension. The presence of a severe chest injury was associated with an increased odds of mortality (AOR 2.8, 95% CI: 1.3, 6.1), while patients injured in intentional events were also more likely to die than patients involved in unintentional events (AOR 4.9, 95% CI: 1.6, 15.6). There was no association between the hospital of definitive management and mortality after adjustment for other variables, despite differences in the protocols for managing these patients at the major trauma services (Level 1 trauma centres). The findings highlight the importance of the need for effective control of haemodynamic instability for reducing the risk of mortality. As most patients survive these injuries, further research should focus on long term morbidity and the impact of different treatment approaches.