This article critically analyses the dynamic role of the Preschool Teachers' Union in Iceland, tracing its strategic moves within the educational and political spheres from inception to the present. The union's formative years were marked by a fight to become a fully fledged union and active participation in foundational negotiations that significantly shaped the working conditions and structural policies of preschool education in Iceland. These efforts ultimately enhanced preschool educators' professional status and working conditions. The union effectively influences wage negotiations, working conditions and policy reforms by leveraging data-driven approaches. The union has also navigated challenges amid neoliberal educational shifts, ensuring teacher representation in public discourses and policymaking with considerable improvements. However, the gains made by the Preschool Teachers' Union had costs, in terms of professional autonomy and integrity. The article also addresses current challenges, highlighting the union's adaptability and ongoing advocacy efforts. The data consist of historical documents and interviews with the present union president.