In this study, the author implemented a problem-based learning (PBL) experience that allowed students in an advanced science methodology course to explore differentiated instruction. Through working systematically in small, collaborative groups, students explored the nature of differentiated instruction. The objective of the study was to examine pre-service teachers' developing conceptions of differentiated instruction (DI) as a way to teach for diversity. The author adopted action research as a strategy to explore students' perceptions of DI in the context of science teaching and learning. Several data collection methods and sources were adopted in the study, including student-generated products, student interviews, classroom observation, and journal writing. Outcomes report on students' perceptions of both the potential and challenges associated with adopting a DI approach to science teaching and learning.