Conspiracy theories are common in both local and international contexts. These theories offer simple explanations to complex problems and events, and they can have negative consequences for individuals and society. This study examines the experiences and perceptions of six high school teachers regarding conspiracy theories within social studies education through semi-structured interviews. The purpose of the study is to shed light on the teachers' experiences of conspiracy theories in their professional roles, the strategies they perceive as useful in handling conspiratorial beliefs, how they respond to students expressing such beliefs, and the conditions they perceive to have in dealing with conspiracy theories in their teaching. The results of the study indicate that teachers perceive conspiracy theories as a growing problem in upper-secondary school and they address this issue by attempting to strengthen students' familiarity with authoritative and trustworthy sources. The results also showcase that active inclusion of conspiracy theories in the classroom can attract students to these theories, but it can also provide an opportunity to spark interest and equip students with knowledge and skills if the theories are approached correctly. Furthermore, the teachers recognized the importance of developing students' critical thinking skills and suggested non-confrontational approaches when responding to students expressing conspiracy theories. They also noted that the response to a student would vary depending on whether the student expresses controversial conspiratorial content. Regarding the teachers' conditions to handle conspiracy theories, they identified the need to broaden and deepen the area of source criticism, as well as the necessity for more time, space, collegial collaboration, as well as professional development to enhance their understanding of effective strategies.