Education for Sustainability (EfS) seeks to empower children with knowledge, skills, values, and attitudes to address global challenges while adhering to sustainability principles. This study investigates the conceptual understanding and pedagogical practices of EfS among early childhood education (ECE) teachers in Norway. Using mixed-methods design, data were collected through reflection notes, surveys, and didactic development projects, revealing fragmented understanding primarily focused on action-oriented, fact-based, and normative aspects of sustainability. The teachers emphasised waste sorting, recycling, and nature experiences, with limited attention to holistic and pluralistic perspectives. Despite curriculum mandates, sustainability had low implementation in ECE educational plans and collaboration meetings. The findings highlight the need for comprehensive teacher education and support to promote EfS and foster agents for sustainability in the context of ECE.