This study examines the role of Namibian secondary school science, technology, engineering and mathematics (STEM) teachers' interest in STEM education and self-efficacy in implementing STEM education in science education curricula. Furthermore, it aimed to distinguish male and female Namibian teachers' interests and self-efficacy regarding STEM education and investigate how different teaching subjects affect them. To achieve this goal, a survey was completed with (n=200) secondary school teachers, both males and females. Data were analyzed quantitatively using exploratory factor analysis and analyzed covariance. The results show that most teachers were highly interested and confident in implementing STEM subjects into science curricula. While Namibian teachers indicated a high level of interest, they also revealed a high lack of interest in STEM, implying that at least some teachers felt bored and meaningless in implementing STEM education. However, gender plays a significant role in teachers' negative self-efficacy, with male teachers being less confident than female teachers in implementing STEM education. Moreover, teachers in the present study have high positive and negative self-efficacy levels regarding implementing STEM education. Therefore, these findings highlight the need for a paradigm shift, especially in the Namibian science curricula, to promote STEM subjects and to improve science education. Potential implications from this research also suggest that teachers' participants benefit significantly from learning within a community by engaging in solutions to real-world problems. [Note: The page range (297-311) shown on the PDF is incorrect. The correct page range is 297-312.]