This guide explains how to design and use a policy brief to translate scientific knowledge into concrete action. It defines the policy brief as a concise summary of the state of knowledge, policy options and recommendations. It stresses the need to understand users’ expectations, needs and preferences in order to increase relevance and impact. Development must include regular exchanges between researchers and users, ranging from questionnaires to workshops. The document details three steps: understanding users’ expectations, structuring the note and validating its relevance with recipients. In terms of structuring, the note should be kept brief (2 to 4 pages, around 1,500 words), with an attractive title, a summary, highlights, an introduction, a brief methodological approach, clear results, a conclusion and realistic, contextualized recommendations. Best practice recommends adapting the tone to the audience, using clear, direct language, limiting jargon, presenting data using simple graphics, and planning dissemination strategies. Involving recipients during preparation and dissemination improves adoption of recommendations. Communication is not enough: an active dialogue must be maintained to support implementation. Finally, a checklist helps to ensure that the note is appropriate, relevant, well-structured and visually appealing. The guide is supported by several organizations, and makes it clear that its content is the responsibility of the authors. It does not necessarily reflect the official positions of USAID.