This study aims to determine a primary school teacher's observations and experiences regarding in-service training on drama method within the framework of collaborative action research model. The first author was invited to offer a 120-hour Drama Course upon request of the teachers in a primary school. In the 14th week, the action research process started with a teacher who wanted to implement the drama method in her classroom. Collaborative action research cycle was consisted of following phases: structuring the lesson plan, implementing, and monitoring the lesson plan in the classroom, teacher's observation of the process, and reflection of the findings obtained through student feedback and reflective diaries. The teacher prepared 4 lesson plans, implemented, and evaluated them in this cycle, which lasted a total of 8 weeks. According to results, Derya teacher actively participated in the process, questioned her practices systematically, and became open to development and change with the students and researcher's feedback. Based on the findings obtained, it is suggested that collaborative action research model in in-service training should be used. Thus, thanks to this model based on practice, it may be possible to reduce the theoretical weight of traditional in-service training and seminars. [This study was presented at the 18th Primary Teacher Education Symposium held on 16-20 October, 2019.]