There is a paucity of research around Differentiated Instruction (DI) in Australian senior secondary education even though this approach has been shown to have the potential to cater for diverse learning needs in inclusive classrooms in other school contexts. Investigating how DI is understood and implemented by teachers in a senior secondary context will allow for a deeper insight into, and possible improvement in, teachers' knowledge and use of the DI approach. This qualitative study focussed on how four teachers from one school viewed DI and how they employed and documented DI practices in their senior secondary classrooms when catering for the needs of diverse learners. The teachers noted positive outcomes such as happy students and a sense of fulfilment for the teacher, as well as enablers for implementing DI effectively, including teacher collaboration and reflection. Challenges to effectively implementing DI were mentioned, such as a lack of time and large class sizes.