Differentiated instruction remains one of the most important frameworks for the global education community to achieve sustainable educational development goals and inclusive education. It is also one of the most critical challenges for teachers in different subjects. This study used structural equation modeling to examine the role of teachers' practices and beliefs in implementing differentiated instruction in physical education. Using a sample of 527 preservice teachers, we found that a growth mindset was the strongest predictor of differentiated instruction, followed by flexible grouping and differentiating the curriculum. In addition, multiple mediation analyses revealed that differentiating the curriculum and flexible grouping mediated the relationship between a growth mindset and differentiated instruction. We also guide teacher educators to develop teachers' growth mindsets and help teachers better understand differentiated instruction in physical education.