This Guidance is designed to help gather better data on internally displaced persons (IDPs) by proposing different methodologies and providing advice on choosing the optimum method for a given country context. The Guidance also examines a series of related issues: how to obtain a better picture of who and where IDPs are, the difficulties of distinguishing them from surrounding communities, and how to compile workable estimates for protection, programming, and advocacy purposes. This Guidance is designed specifically for senior technical-level UN and NGO decision-makers at the country and sub-regional levels. It is also for those tasked to conduct a profiling exercise who may be experts in conducting demographic surveys but may not necessarily know much about IDPs.