There is wide acceptance that there are teacher shortages, particularly in physics, chemistry and mathematics, and in rural and hard to staff schools. An issue that arises because of this shortage is teachers teaching subjects that they are not qualified to teach. In this paper, I draw on my research and that of others to outline the issues for teachers who are teaching outside their subject areas, or "out-of-field", particularly at the junior secondary level, and particularly in Mathematics or Science. This practice is prevalent in many Australian schools and it has enormous implications for policy and practice around school governance, funding arrangements and structures associated with continued teacher development, and initial teacher education. In this paper, I refer to only the teacher perspective, but this issue ultimately impacts on the quality of the education we provide students. I conclude with recommendations for school governance practices, teacher education and professional development. (Contains 3 figures and 3 tables.)