Despite the growing prominence of STEM disciplines in contemporary society, relevant studies indicate a concerning trend: a decline in students' interest and engagement in these fields. This research included 1,045 students from four grammar schools in Serbia. The study utilizes a quantitative research design: data were collected through an online questionnaire. Key variables: end-of-term marks in STEM subjects, gender, parental education, family size, and place of residence were analyzed following the answers of respondents. Students were divided into two groups, STEM (435) and Non-STEM (610). The results indicated that the students enrolled in STEM-focused programs demonstrated significantly higher academic performance in STEM subjects during primary education compared to their peers in Non-STEM tracks. Additionally, the study identifies potential relations between students' interest in STEM and factors such as gender, parental education, and place of residence, with no significant effect found for the number of siblings. Specific sample and custom-designed questionnaire, highlight the need for future research with a broader and more diverse sample, incorporating additional socio-demographic factors and qualitative methods for a deeper understanding of students' engagement with STEM fields.