This paper reports on a survey conducted with Australian Education Union (AEU) members that sought to investigate the extent of commercialisation in Australian public schooling. Commercialisation is the creation, marketing and sale of education goods and services to schools by private providers. Commercial services commonly include the provision of curriculum content, assessment services, data infrastructures, digital learning, professional development for teachers, supply of contract and replacement teachers and school administration support. Our data suggest that commercialisation is now commonplace in Australian public schools. Commercialisation, however, has had a long history in schools, beginning with commercially produced textbooks which have been around since the early 20th century. Teachers in the survey reported that resources and curriculum materials that supported their development of innovative learning experiences were important still. However, teachers’ expressed concern that increasing commercialisation would lead to an intensification of the de-professionalisation of teaching. In particular, teachers expressed concern at the ways testing was driving their work and how this opened up opportunities for commercial providers. This paper explores these teacher concerns and in particular, focuses on teachers’ perceptions of how commercialisation is impacting their work, their students’ learning and their personal wellbeing. Teachers’ concerns about the growing phenomenon of commercialisation and their argument that they have less autonomy over what to teach and how to teach it, as well as the idea that private providers might replace teachers completely, necessitates the need for urgent public debate about commercialisation in schools and where we should fight to draw the line. The paper critically considers this range of issues and stresses the pressing need for teachers’ voices to be much more involved in contemporary policy making.