Examining the development of horizon scanning, an approach primarily used to retrieve and organise information from different sectors, this chapter recognises its efficiency in identifying the early indications of threats, a method which then enables policy-makers and researchers to respond quickly to hazards and risks. Different horizon-scanning approaches, such as manual or automated searches, are assessed by the authors in relation to scope selection, input gathering, data sorting, result analysis, output utilisation and process evaluation. This allows for the most effective horizon-scanning approaches to be identified, and the different purposes for each approach. This chapter therefore explores the most effective ways in which to use horizon scanning, specifically in policy-making, proving the necessity of its use in the future.