Organ donation is a crucial aspect of healthcare, yet, the number of donors is insufficient to cover the demand for transplant procedures. In the European Union, around 15 people die each day waiting for a life-saving organ. National policies differ greatly among countries, but it is unclear how successful policies affect Deceased Organ Donation rates when introduced in new settings. This paper explores the use of Agent-Based Social Simulation (ABSS) to inform organ donation policymaking. Simulations provide policy actors with a safe environment to investigate the consequences of different policy interventions without the risk of harming people. We present an agent-based model of the Swedish organ donation system, where we can investigate the impact of Spain’s policy approach, which produced the highest DOD rates in Europe. The results highlight the potential of ABSS as a tool for designing policy interventions in complex healthcare systems. Further developments can enable policymakers to identify successful strategies and monitor their effect to evaluate policy progression.