STEM (science, technology, engineering, and mathematics) education is vital for incubating future scientists, engineers, and inventors. Teaching and learning in STEM education require teachers and students to employ design thinking and multi-disciplinary knowledge to formulate new solutions for emerging problems. School teachers are facing multiple challenges in implementing STEM education. With the application of the Self-efficacy and stages of concern theories, this quantitative study (with 235 teacher respondents) aims to unearth Hong Kong teachers' responses regarding STEM education. The results show that 5.53% of the respondents regard themselves as "well prepared" for STEM education. On the other hand, the respondents have intense "information", "management", and "consequence" concerns about implementing STEM education in schools. The findings reflect that there is an urgent need to provide teachers with articulated professional development, pedagogic support, and curricular resources for empowering them to implement STEM education in practice.