The purpose of the present study was to investigate teachers’ declarative metacognitive knowledge of higher order thinking skills. This was a qualitative study conducted within the educational setting of in-service science teachers’ courses. The main finding is that teachers’ intuitive (i.e., pre-instructional) knowledge of metacognition of thinking skills is unsatisfactory for the purpose of teaching higher order thinking in science classrooms. A general practical implication of this study is that courses which prepare teachers for instruction of higher order thinking should address extensively the issue of metacognition of thinking skills.