This review was commissioned by the Internal Working Group on Internally Displaced Persons in order to bring greater clarity and consistency to the interpretation of UNHCR policy and operational guidelines on involvement with IDPs. The review analyzes certain variables that have influenced or determined UNHCR’s involvement with IDPs with a view to indicating how UNHCR could be more consistent and predictable in its decision making processes. The review is not an examination of all aspects of UNHCR’s decision to engage or not to engage in IDP situations, nor is it a review of UNHCR’s policies on IDPs.