To mark the 100th anniversary of the International Labour Organization (ILO), the Belgian NGO Solsoc and the CETRI wanted to question the social and soli-darity economy (SSE), which is at the heart of its strategy to promote Decent Work. In effect, various studies have highlighted the SSE as the best tool for promoting Decent Work. The ILO shares the view that “the social and solidarity economy contributes to the four dimensions of the ILO’s overall objective of Decent Work”.But how can we ensure that the SSE is the driving force behind the spread of Decent Work and its four pillars, namely job creation, the right to work, social protection and social dialogue ? How can it both “create a movement” and connect with other social movements, including trade unions and women’s movements ? Under what conditions can it not only help meet needs, but also represent a transformative power and, beyond that, an alternative to the economic model ? These questions, strategies and challenges are examined here on the basis of analyses, expertise and experience from the South, by giving a voice to organisations, health mutuals, trade unions and Solsoc’s partners, who are all actors in this transformation and alternative on a daily basis.