This chapter examines the implementation of the whole school approach (WSA) to education for sustainable development in the United Nations Economic Commission for Europe (UNECE) region through 34 national reports submitted by its member states. The reports were analyzed under six axes: schools’ vision, ethos, leadership, and coordination; curriculum; pedagogy and didactics; school management and operations; professional development; and school environment. Despite a clear orientation toward a whole school approach, the analysis showed that within the UNECE region, the six axes were unevenly addressed and some were poorly reported, leading to a partial view of the state (e.g., school infrastructure). The results are discussed in the framework of the whole school approach literature providing insights on ways to strengthen the approach and eliminate gaps and challenges through the new implementation framework of the UNECE Strategy on ESD 2021–2030.