Working with ethnoracially diverse student groups is a reality in most K-12 classrooms. However, studies of the impacts of professional development for cultural responsiveness have tended to use a range of approaches such as action research, video reflections, and coaching, making it difficult to tease apart the effects of each one. The purpose of this study was to focus on how action research, specifically, influences educators' culturally responsive practices. Participants found that the action research process promoted their agency to effect positive change in their schools, a key component of culturally responsive education. Although participants found it challenging to balance learning the nuances of action research and culturally responsive education simultaneously, they appreciated this as a productive struggle and adopted the same growth mindset for themselves that they encouraged in their students. Based on our results, action research appears to be a promising form of professional development for enhancing culturally responsive practices.