Engaging in a nuclear power programme is a major undertaking with long term implications for at least hundred years. Key factors that may influence decision makers in their commitment to a nuclear power programme are of different nature, including political, socio-economic, financial, environmental, technical, or public acceptance. In line with the guidelines of the IAEA Milestones Approach, a comprehensive report corresponds to the attainment of Milestone I (ready to make a knowledgeable commitment to a nuclear power programme) and provides the rationale and strategy for pursuing a nuclear power programme, supporting the development of a national position. This publication intends to support Member States that are developing comprehensive reports by sharing the experience of the ones that have already completed this process or are well advanced on this path. The publication highlights similarities and differences in the approaches adopted, recognizing that there are several different ways and formats for developing such a report.