This research aims to determine the taboo concepts that teachers tend to avoid during philosophical discussions with children and why these concepts are considered taboo. We focus on teachers’ experiences using phenomenology, a qualitative research design. For this purpose, we used the snowball sampling method to reach 73 teachers and they answered a questionnaire consisting of 5 open-ended questions. We carried out semi-structured interviews with 7 of these teachers to get in-depth responses and to reflect different views on the subject. Accordingly, 65 teachers had one or more taboos, while 8 teachers did not have any taboos. Death, religion, and sexuality emerged as the most prominent taboo concepts. According to the participants, taboos are formed because of children, teachers, and society. The participants expressed that taboos could have a negative impact on the child, the discussion environment, and the teacher, and they offered solutions. Teachers need to develop a better level of competence in engaging in philosophical discussions with children in order to overcome taboo concepts. Teacher training sessions can be organized to address how to approach taboo concepts and how to select children’s books that contain such concepts. Research can be conducted on engaging taboo concepts in philosophical discussions with children. This body of research can explore the impact of questioning such concepts on children’s perspectives toward them.