The use of decontamination methods and techniques are complex, and an integrated assessment of technical performance, environmental factors, and costs is necessary for selection where large decontamination projects in the Nuclear Industry requires a combination of processes. This publication focuses on decision making in the planning of nuclear and radiological decontamination projects and provides guidance on the selection of the most appropriate approach. It includes consideration of relevant factors and how individual factors are weighed, merged and combined leading to an integrated decision on the preferred approach. The publication is expected to be of use to all those involved in the planning of a decontamination project.