Research relating to the nature and purpose of 'design' activity across education sectors has accelerated in recent years as governments and policy makers throughout the world highlight the importance of skills such as creative problem-solving and innovation. Within secondary schools, responsibility for teaching and learning through design is often assigned to Technology and Engineering subjects, however, gaps tend to exist in relation to what different teachers understand and experience about the teaching and learning of problem-solving and design in their classrooms. In this exploratory study, a small group of practicing secondary school teachers completed a one day training workshop where they were introduced to new knowledge and pedagogical skills relating to design problem-solving using a classroom intervention called 'Designing Our Tomorrow'. The teachers participated in a focus group discussion before and after the workshop in which they discussed their experiences in teaching design. Conceptual Metaphor Theory (CMT) (Lakoff & Johnson Metaphors we live, University of Chicago Press, 1980) was employed to highlight the figures of speech used by the teachers during the focus groups and from these a number of conceptual metaphors were identified that described their understandings and experiences of teaching design problem-solving. In synthesizing the broad theoretical base relating to understandings of design problem-solving and CMT together with the findings from the one day professional development workshop, the paper highlights the potential value for researchers in using CMT to unpack teachers' views on how design problem-solving is taught and learned in schools. Finally, the paper reveals a potential new space to inform and evaluate future professional development of Technology teachers, particularly where the focus is on complex and difficult to define concepts such as design and problem-solving.