Studies have shown that various factors (the role of formal education, informal education, and community) contribute to the lack of participation in STEM and STEM careers. This research aimed to understand the multi pathways of factors contributing to the interest in STEM careers (STEM careers in physical sciences and STEM careers in life sciences). This research was a survey research which administered a questionnaire randomly to 1485 secondary school students (14 years of age). Data analysis was based on the Structural Equation Modeling (SEM) approach using Analysis of Moment Structures (AMOS) to test the hypothesized model. A model containing five constructs, namely environmental factors (learning experiences, media, social influences), self-efficacy in science, technology, engineering and mathematics respectively, perceptions of STEM careers and interest in physical sciences and life sciences STEM careers was proposed in this research. The results show that students' interest in life sciences based careers is influence by their self-efficacy and perceptions of the career. Meanwhile, students' interest in physical sciences based careers is influence only by their self-efficacy and not influence by their perceptions of the career. The need to improve students' self-efficacy through STEM learning experiences is imperative to ensure continued interest in STEM careers.