The construction industry has been characterized as one with a poor safety culture and that attempts to improve the safety record will not be fully effective until the safety culture is improved. Given that you cannot improve what you cannot measure, this paper utilises the system thinking approach in a novel way to objectively measure organisational safety culture. The paper describes a system dynamics model that captures the interaction among key enablers of safety culture and their individual, as well as combined, impact on safety performance. The paper argues that only through system dynamics modelling, organisations could be capable of properly assessing the maturity level of their safety culture, which in turn would lead to optimum resource allocation in the quest to improve safety performance. The model, presented in the paper, comprises five major enablers namely Leadership, People, Policy & Strategy, Partnerships & Resources, and Processes. The reported numerical sensitivity analysis sheds some light on the causal relationships among these enablers and demonstrates their level of influence on the overall safety culture score.