High-quality Science, Technology, Engineering, and Mathematics (STEM) education provides unique opportunities for students' futures. STEM education requires integrating multiple disciplines and promotes students' problem-solving skills when engaging with real-world problems like engineers. Teachers have prominent roles in helping students develop basic concepts, connect their interests to their abilities, and sustain their curiosity from the early years. The present study used a predictive correlational survey design to investigate students' STEM career interests and the effects of teacher-related variables: teacher attitudes and self-efficacy beliefs. The participants were 421 middle school students and 160 teachers randomly selected from the target population. STEM Attitudes Scale and Teacher Self-Efficacy Scale for STEM Practice were used to collect data from teachers, and STEM Career Interest Scale (STEM-CIS) was used for data collection from students. Normality assumptions were tested, and parametric tests were used. One sample t-test was used to compare students' observed mean scores to the expected mean scores and multiple linear regression to investigate the predictivity of teacher attitudes and self-efficacy beliefs on student interests. The results revealed positive weak, and moderate relationships between teacher attitudes, self-efficacy beliefs, and student interests. Additionally, teacher efficacy beliefs had stronger predictivity on student interests than attitudes had. [Note: The page range (204-216) shown on the PDF is incorrect. The correct page range is 204-215.]