This contribution offers a reflection on the practical use of the Theory of Change (ToC) through the analysis of a case study. The case examined concerns the evaluation of the CoMix project, funded by the Social Innovation Fund (SIF), which includes co-housing initiatives targeting vulnerable groups – young people with disabilities and NEET youth – as well as the activation of multifunctional hubs aimed at bringing public administration closer to peripheral urban areas and fostering processes of social and labour inclusion and community engagement across Tuscan territories. The evaluation of the project provides an opportunity to reflect on the role of the ToC in evaluation practice, highlighting both its flexibility and its practical limitations. In particular, the case shows how the ToC, although widely adopted in evaluation practice, may lead to unsatisfactory outcomes when it remains anchored to the initial assumptions about how an intervention is expected to work and is not adequately adapted to changes in context and in the evaluation process.