STEM education plays a significant role in a country's economy growth. Consequently, innovative and advanced careers in STEM domains are fast emerging because more people are employed in STEM related professions. Literature has identified various determinants of STEM career and STEM major choices including gender, self-efficacy, parental influence, outcome expectancy and aptitude towards science and mathematics. While extensive literature exists on STEM major choices, it is predominantly concentrated on Western countries. This study aims to fill the gap by providing empirical evidence of gender, ethnicity, and high school grades as determinants of STEM major choice among undergraduates in a developing country. The results expand the understanding of how demographic factors influence academic choices in non-Western settings. Practically, the findings can inform policy makers on strategies to encourage STEM enrolment among diverse student populations in Malaysia.