This study focuses on science, technology, engineering and mathematics (STEM) education teachers' perspectives on integrating indigenous knowledge systems (IKS) into a multidisciplinary STEM framework to promote sustainability. The aim is to understand how integrating the values, ethics and worldviews of the global community can contribute to a sustainable mindset. Through an examination of the research background and pedagogical foundations, as well as a review of existing literature, it becomes evident that teachers' perspectives are pivotal in fostering a sustainable mindset among students. To encourage social dialogue that has the potential to evolve teachers' perspectives, a 6 month workshop focused on dialogic argumentation was provided to a group of basic education and university STEM teachers. The workshop aimed to explore the evidence- and reasoning-based arguments that influenced their perspectives regarding the role of IKS in STEM education. Analysis of data collected through questionnaires and interviews yielded the following findings: (a) initially, most teachers had mixed feelings about the role of IKS in STEM education for sustainable development; (b) a significant number of teachers reported that the dialogic argumentation workshop helped them transition from a negative to a positive attitude towards acknowledging the complexity of the role of IKS in promoting various approaches to achieving sustainability goals; and (c) several others, particularly university teachers, attributed IKS with the potential to enhance reflective reasoning in order to solve complex sustainability problems. The implications of these findings for classroom practice, particularly in terms of utilising IKS to enhance STEM teacher education, are highlighted in the paper.