Research on the implementation of Culturally Relevant Education (CRE) in STEM Education suggests that CRE improves achievement and cultural competence in math and science (Aronson & Laughter, 2016). CRE implementations in math and science remain relatively low and sporadic (Brown et al., 2019; Neri et al., 2019). Scholars have stressed that more effort is needed for preparing teachers to translate CRE theory into practice, particularly for math and science subjects (Brown et al., 2019). There is a dearth of literature review of studies that focus on in-service science teachers’ understanding of the principles of CRE and how to implement them in middle and high school science classrooms (Brown & Joyce, 2024). In addressing this research gap, this paper seeks to review and analyze in-service science teachers’ understanding of CRE in 6–12 settings based on research published since 2020. The foundational frameworks of CRE are described and an expansion of their key tenets is proposed. Findings show, on average, that teachers understood the tenets related to Academic Competence very well. There is still work to be done to improve their understanding and perception of tenets related to Cultural Competence, developing Sociopolitical Consciousness, and a Critical stance on epistemology and axiology of western knowledge. Teacher education programs need to align their agendas along the tenets of CRE. Teacher education programs focused on STEM teachers should incorporate a critical examination of science epistemology in their programs of study.