This paper responds to the call for the need to develop professional development practices for leaders, supervisors, teachers, and student guidance within the framework of international standards, particularly in line with the Kingdom of Saudi Arabia’s (KSA) vision 2030 (KSA, 2019). The current study aims to identify the obstacles and challenges for implementing sustainable professional development methods for teachers in KSA, who had participated in a ten-month Australian cross-national STEM professional development program. In addition, the teachers also participated in an immersion in Australian schools that lasted for 11 months. This paper reports on a sample of 22 male and female teachers coming from primary and secondary KSA schooling contexts. The participating teachers in the study were those who had participated in the Australian STEM immersion professional learning program in 2019-2020. Drawing from previous studies (Ermeling & Yarbo, 2016; Greene, 2015; Kayi-Aydar & Goering, 2019; Piqueras & Achiam, 2019), we have proposed a framework involving four methods for sustainable professional development for STEM teachers: professional learning communities, communities of practice, action research, and the outside expert. A mixed-methods research design was applied including three methods: individual interviews, open-ended questions to identify the proposed plan of STEM teachers’ implementation of the sustainable professional development methods. Also, a questionnaire to identify obstacles to the implementation of sustainable professional development methods from the viewpoint of STEM teachers was also employed. The results showed that the most prominent obstacles to the implementation of the sustainable professional development methods by STEM teachers in the Saudi educational system where there is no coordination in the school meetings schedule for the members of the professional learning STEM education community, there is no clear plan for communities of practice of STEM education, teachers’ overload teaching duties, lack of coordination between schools to benefit from STEM experts. Implications of our study reside in developing teachers’ ongoing STEM professional development opportunities through execution of a sustainable model of collaborative teacher communities in KSA. Suggestions for curriculum stakeholders and administrator’s coordination and supporting teachers’ ongoing participation and implementation of professional development programs are discussed.