ABSTRACT This article reports on research conducted in New South Wales, Australia, which investigated why students from linguistically and culturally diverse backgrounds in some schools achieve consistently higher levels of educational growth than students in other schools with similar demographics. The purpose of this research was to learn more about high growth schools, and the factors that contributed to their students’ educational success. Based on analysis of data from six high growth schools, the article argues that the intersecting elements of building constructive relationships within and between staff and students; of valuing expertise in English as an Additional Language (EAL) education; building teacher professional knowledge; and promoting systematic school-wide implementation of EAL pedagogical principles were pivotal to students’ successful educational outcomes. However, it also argues that the effective implementation of these factors is dependent on the nature and quality of leadership in the schools – a leadership that recognises and values these factors in school-wide programs and provides space and support for their implementation.