This paper explores the institutional effects of inter-organizational collaboration, focusing on the case of Mère et Enfant (a small NGO in Palestine) over a four-year period. The authors argue that collaboration can act as a source of change in institutional fields through the generation of proto-institutions—new practices, rules, and technologies that transcend specific collaborative relationships and may become fully institutionalized if they diffuse throughout the field. They find that collaborations characterized by high levels of involvement among partners and high embeddedness in the institutional field are more likely to generate proto-institutions. The study contributes to institutional theory by providing empirical evidence on how collaboration can initiate change and by highlighting the importance of both internal dynamics and external connections in the process of institutional innovation. The authors also discuss the methodological implications of using qualitative approaches to study institutional phenomena.This paper explores the institutional effects of inter-organizational collaboration, focusing on the case of Mère et Enfant (a small NGO in Palestine) over a four-year period. The authors argue that collaboration can act as a source of change in institutional fields through the generation of proto-institutions—new practices, rules, and technologies that transcend specific collaborative relationships and may become fully institutionalized if they diffuse throughout the field. They find that collaborations characterized by high levels of involvement among partners and high embeddedness in the institutional field are more likely to generate proto-institutions. The study contributes to institutional theory by providing empirical evidence on how collaboration can initiate change and by highlighting the importance of both internal dynamics and external connections in the process of institutional innovation. The authors also discuss the methodological implications of using qualitative approaches to study institutional phenomena.