Construction activities involve various risks, which can cause fatal major and minor accidents. The construction of Mass Rapid Transit (MRT), which is the most prestige urban rail infrastructure project in Malaysia, also exposed to those accidents. Both fatal and non-fatal accidents have high significance in economic burden to the MRT project stakeholders. However, it is very difficult to quantify the costs of these accidents. The objective of this study is to explore a method to calculate accident costs during the construction of urban rail infrastructure projects. To derive accident costs at construction sites, an accurate structure of the data collection system is very essential. This study is based on previous research that classifies the accident costs into two basic categories, which are direct costs and indirect costs. Measuring accident costs and providing the most specific variables are crucial as the calculations should be as detailed as possible for the accurate provision of project budget as well as cost for controlling and monitoring purposes. This study can also increase awareness of accident costs in urban rail infrastructure projects.