This article draws from a qualitative study of seven beginning teachers' perceptions of diversity over a period of 6-18 months. The study found that while initial teacher training had broadened their understanding of diversity and its implication for teaching, it was established pedagogical practices in their schools that influenced the novices' ongoing understanding of responsiveness to learner diversity. For these novices, the influence of the structures and systems of their school contexts began to restrict their pedagogical stance. Based on the reported findings and wider research data, the article argues the need for ongoing critical professional support for beginning teachers who can deepen their understanding of learner diversity and its pedagogical implications. It underscores the importance of a genuine partnership between schools and teacher education providers to enable the continuation of critical professional support for novices, particularly in contexts where there are no mandatory links between preservice programmes and beginning teaching like New Zealand, where this study was undertaken. The author contends that it is unrealistic otherwise to expect beginning teachers not only to challenge entrenched practices but also to sustain the efforts of initial teacher education programmes in preparing them to be responsive to diverse learners.