In an increasingly inclusive educational environment in which Caribbean governments have signalled their commitment to Education for All, teachers are expected to respond to students’ diversity through differentiated practice. There has been no empirical research about the response of practicing teachers involved in the UWI Diploma in Education programme to differentiated instruction. During the 2016/2017 academic year, forty science and physical education teachers were exposed to a session on differentiated instruction and were asked to plan and enact a lesson for differentiation and to reflect on the experience. This qualitative case study reports on the findings of teachers’ perceptions of a differentiated approach to lesson planning and enactment. Qualitative data collection included lesson plans and written reflections on the lesson. Analysis of the data revealed that the majority of teachers differentiated by process and that none of the teachers differentiated by content. Analysis of teachers’ reflections revealed themes related to the inputs, outcomes, and challenges of planning for and enacting differentiated lessons. The implications of the findings are discussed.