It is an indisputable fact that teachers need feedback on their teaching processes. In this respect, supervisory practices of school principals play an important role in meeting such needs of teachers. It is expected that the supervision activities conducted in cooperation with teachers in accordance with the principles of supervision will contribute to teachers' professional development by producing efficient feedback. This study aims to determine the views of Religious Culture and Moral Knowledge (RCMK) teachers on supervision, counseling and professional development activities organized by school principals. The study was designed through the survey model, and by using the mixed method, which is defined as the combination of qualitative and quantitative techniques in a study or consecutive studies. The reason for using the mixed method is to clarify and elaborate on data by comparing the quantitative data collected through questionnaires from a larger number of participants with qualitative data obtained from a limited number of participants. The exploratory sequential mixed methods design used in the study began with collecting and analyzing quantitative data that responds to the research question, followed by obtaining and analyzing qualitative data. The data collected from the quantitative research become more significant along with the data in the qualitative research to achieve in-depth analysis.