This research was aimed to know forms and strategies and analyze similarities and differences of Islamic religious teacher’s professionalism development in Indonesia and Malaysia. This research carried out qualitative approach in the form of library research. This research used Miles and Huberman model to analyze the data consisting of data reduction, data display, and conclusion drawing/ verification. The findings of the research show two forms of teachers’ professionalism development in Indonesia and Malaysia namely institutional-based development and individual-based development. In Indonesia, two development strategies for high school religious teachers are found namely education and training and non-education and training. Meanwhile, in Malaysia, four strategies are found namely courses for improving teacher professionalism, investigation and research, education for self-development as well as updated education development. Four similarities of teachers’ development in Indonesia and Malaysia are found consisting of similar development form, the committees existence, coaching activities, and coaching strategies, while two differences are found consisting of different coaching activities, and different number of strategies.