A teacher must be aware of the importance of teaching higher order thinking skills (HOTS) to prepare young generations in 21^st Century. But in reality, many teachers find difficulties in teaching HOTS. This research aims to describe teachers’ difficulties in teaching HOTS in the classroom. The research is a descriptive explorative research by means of qualitative approach. The data were collected from questionnare. This research involved 10 high school mathematics teachers in Yogyakarta, Indonesia. The result of the research shows that the teachers still find difficulties in teaching HOTS in the classroom, those are (1) teachers’ knowledge about HOTS is still low, (2) teachers’ difficulty in delivering apperception to students, (3) teachers’ difficulty in designing and applying the assessment based on HOTS, (4) teacher’s difficulty in delivering HOTS based learning materials, (5) teacher’s difficulty in making learning media based on HOTS, and (6) teachers’ difficulty in preparing learning tools based on HOTS.