The study reported in this article aimed at exploring what teachers know and do about fostering higher-order thinking skills in teaching science, and how they see themselves involved in achieving this end. Data were collected through semi-structured interviews with 11 teachers experienced in teaching high school physics, which is considered a relatively difficult but well-established discipline. The findings highlighted a diversity among the teachers in four areas: meta-strategic knowledge of the concept of higher-order thinking; practical utilization of instructional strategies related to fostering higher-order thinking in the classroom; beliefs about students' abilities to acquire higher-order thinking skills; and self-perception regarding teaching towards higher-order thinking. Regarding the second area, for example, some of the teachers reported using teaching strategies in class that could impede the development of students as autonomous thinkers; others occasionally try to foster higher-order thinking among their students but regard this as a way of conveying subject content better; only a minority of the teachers see the fostering of higher-order thinking as an important objective of teaching physics. In summary, teachers are frequently puzzled or uncertain about the entire issue of fostering higher-order thinking in school. Introducing elements of constructivist pedagogy combined with the specific steps aimed at fostering higher-order thinking into the science class is required to make the development of higher-order thinking a regular ingredient in science teaching within the current schooling. (Contains 1 figure and 1 table.)