Purpose: In light of the extensive empirical evidence that implicit theories have important motivational consequences for young people across a range of educational settings we seek to provide a summary of, and personal reflection on, implicit theory research and practice in physical education (PE). Overview: We first provide an introduction to the key constructs and theoretical propositions associated with implicit theories. We then include a brief summary of the research findings on ability beliefs in school PE, which we draw on to identify several key issues that we feel are crucial to furthering our understanding of this topic. We conclude by offering a number of ideas for future research and discuss the potential misinterpretation of implicit theories when applied to professional practice in PE. Conclusions: We argue that researchers need to address more nuanced questions around implicit theories to prevent this area of inquiry stalling. Moreover, we need to provide teachers with more specific recommendations to help them integrate theory and research into practice.