In today's globalised world, many issues have become controversial. These controversial issues affect society and the individuals who form them. It is inevitable that these topics are brought into social studies classrooms, because this learning area is profoundly related to society. Social studies teachers' behaviours, attitudes, and professional knowledge are crucial in teaching controversial issues. The goal of this study was to investigate social studies teachers' opinions and practices regarding teaching controversial issues in Turkey. The study utilised a mixed method in which both quantitative and qualitative research methods were used. The quantitative data for this study were collected from 646 social studies teachers in different cities in Turkey. The qualitative data were collected through observation of eight social studies teachers who were working in schools situated in areas at four different socioeconomic levels in the Kirsehir province. The content analysis method was used to analyse the qualitative data. The results indicated that there are differences between the teachers' opinions and their practices in teaching controversial issues. The study also found that teachers are faced with academic, professional, and emotional challenges in teaching controversial issues.