This study is the second in a planned series of qualitative inquiries to investigate how some Australian educators use differentiated instruction (DI) in a secondary school setting. A small-scale study was conducted using individual, semi-structured interviews with seven teachers and two school leaders via Teams, a video conferencing platform. Using thematic analysis, two major themes were identified in the data, namely: perceptions of DI and key guiding DI principles. Results indicated that teachers and school leaders have a good understanding of differentiation and are responsive to the needs of the diversity of student abilities in this educational setting. This includes pedagogies such as designing learning activities to maximise educative opportunities for all students, pre-planning lessons and collecting student data to inform teachers' understanding and capacity to plan for student readiness differences, using scaffolded formative and summative assessment, arranging flexible learning groups, and employing adaptable teaching processes that support all learners. The findings are a starting point to further explore and expand on how Australian educators use DI strategies and approaches in their mainstream schools.