The nuclear sector has in recent years been placing increasing attention on the need to better understand variations between cost estimates for the decommissioning of nuclear power plants, as well as the relationship between estimated and actual costs, and the apparent escalation of these costs. Building on previous work by the Nuclear Energy Agency, Cost Benchmarking for Nuclear Power Plant Decommissioning examines approaches and methods for the benchmarking of nuclear power plant decommissioning costs. Particular focus is given to identifying key factors, drivers and constraints to implementing cost benchmarking. These factors are addressed from a broad range of perspectives in order to develop a roadmap for implementation that will garner sufficiently broad support from a wide base of interested stakeholders. The report also identifies a number of perceived barriers that may impede the implementation of benchmarking for decommissioning. Co-ordinated efforts and further analysis will be needed to help remove these barriers.