This research aims to analyze the role of collaboration in the supply chain in the context of transitioning to a circular economy. The textile and fashion industry was chosen as the focus of this analysis due to its status as one of the world s largest polluters. Various circular practices have been applied to this industry as alternatives to addressing environmental issues. Consequently, the research identified several initiatives related to textile reuse, remanufacturing, optimization, and waste utilization. To understand how actors in the same supply chain collaborate to promote these initiatives, a multiple case study approach was employed, involving 17 semi-structured interviews with different stakeholders in a textile supply chain located in the city of Rio de Janeiro. The method utilized was a qualitative study based in an inductive approach, employing Grounded Theory for data analysis. The results identified three important conceptual dimensions in the discussion of collaboration in this chain, namely: (i) circularity implementation, (ii) social aspects, and (iii) governance. The aspects identified in these dimensions indicate that although there are advancements and the initiatives yield positive impacts, they are observed as efforts of specific groups in the chain rather than being integrated across the entire chain. Regarding social aspects, there are contextual issues in the industry and the initiatives themselves that reveal contradictions. Lastly, in terms of governance, there are important aspects regarding the relationships between the involved parties.