In this study, it is aimed to evaluate teachers' opinions on school principals' classroom supervision task in schools. The study group of this research in which phenomenological model among qualitative research methods was used consists of 8 teachers working in Tepebaşı district in Eskişehir and chosen by means of convenient sampling among purposeful sampling methods. The data obtained using semi-structured interview technique were analyzed using descriptive and content analysis techniques. The results indicate that teachers used metaphors such as "waste, dinosaur, torture, divine comedy, yield meter, Tüvtürk periodical vehicle examination, tea spoon in the glass of someone who does not use any sugar, and detective". Most of the teachers stated that the school principal's role in the course supervision process should be guiding. It was found that none of the teachers thought that school principals could effectively perform their supervisory roles. The results also show that teachers appreciated the application in terms of its effectiveness since it motivated teachers to be prepared for the lessons, to be planned, programmed, to transfer their experience, and to take responsibilities. On the other hand, it was mostly criticized for the unnecessary paperwork, favoritism and discrimination, stress, and reaching wrong judgments due to lack of time. In addition, the majority of the teachers stated that the course supervision should be done by the teachers of the field at issue. In the study, it was concluded that the teachers who do not evaluate the classroom supervision process performed by school administrators as professional do not consider the supervision process as necessary. In general, the study suggests that the supervision should be done by individuals who have a modern understanding of supervision and who are experts in guidance and counseling.