This study investigates how process drama, with a special focus on the teacher-in-role strategy, brings about change in an L2 teacher’s practice. As a reflective practitioner researcher, the teacher who aims to integrate drama into L2 classrooms investigates how her practice changes during the planning phase of her workshops by analyzing her reflective journals through thematic analysis, interpreting the analysis findings and relating them to data collected through observations and interviews. Both cases of teacher-in-role used within the conventional teacher frame and that used beyond the frame were present. In the former case, teacher-in-role resulted in making a teacher-centered pre-scripted performance. However, in the latter case, the teacher being in role created a drama world where the improvisational and spontaneous side of teacher-in-role was developed, resulting in changing the teacher’s practice as follows: First, the teacher-in-role strategy encouraged the teacher to find ways to enhance learners’ commitment to the drama experience by engaging them in improvisation. Second, adopting the strategy led the teacher to exercise imagination, being sensitive to learners’ responses. Lastly, the teacher taking on a role made the teacher think of ways to provide L2 support that promotes the process of co-constructing the drama world.