According to existing literature, bank robberies can have a considerable impact on the people involved (employees, customers, and police officers), even if the direct economic losses are negligible. Consequently, this article presents a model to assess the risk of bank robbery, with the aim of reducing the impact on the people and prioritizing the investments in security measures. It is based on the MIVES (Spanish acronym for the Integrated Value Model for Sustainability Assessment) method and it was combined with Monte Carlo simulation as a way of taking into account the uncertainty. Correlations were also modeled, for simulation purposes. Indicators for addressing issues related to security features, employees, operational procedures, and physical and social environment were defined. The model was applied to two fictitious but realistic sets of cases. The first simulation provides a quick overview of the risk level of a fictitious bank, before collecting the full set of data from hundreds or thousands of branches. The second simulation analyzes the risk variation of a specific bank branch over time. The model was also used to assess the risk index of 636 real branches belonging to a Spanish bank. All the results are presented and discussed in depth. The model allows the user to identify the weak points of a branch, so that corrective measures can be taken.