In the dissertation Films to change the world – production and distribution of social impact documentaries, we investigate a new methodology of making works of this genre from the association of documentary narrative with a strategic communication project. The social impact documentary is built to be the center of a larger project, aiming to propose objective transformations in society, or even actions in order to contribute to a change of mentality regarding specific problems. Activists, civil society organizations and engaged sympathizers begin to act together with the film team, basically through crossmedia and advocacy practices, expanding its audience reach and persuasive potential. In the same way, they can use the documentary to foster debates in their home groups, in a win-win game. In methodological terms, we start from the beginnings of the British social documentary, with civic education project through cinema, to approach contemporary initiatives, dialoguing with authors such as Brian Winston, Thomas Austin and Jane Chapman, with research that helps to understand the main issues in around the conditions of existence and the development of the forms of production of documentary cinema; We also deal with distribution issues; and the audience in its broadest sense, considering the historical contexts dictated by technological, market and public behavior issues. We will also see how the impact campaign of documentaries is organized from two Brazilian case studies: Boy 23 – The Forgotten Boys of Brazil (BR, 2016), and 4All (BR, 2016).