This study aims to investigate the characteristics of students who switch versus those who do not switch when they transition from upper secondary to higher education. The data from 1338 students randomly selected from 21 HEIs in Cambodia in 2020 found that upper secondary school students are more likely than not to switch academic majors when they enter higher education. The tendency to switch is more common for female students in science-track, most of whom chose non-STEM majors such as business, management, accounting and finance. Probit analysis revealed that the decision to switch is influenced by individual academic performance and interest in science and mathematics at upper secondary school, household's socioeconomic status, higher education institution (HEI)'s location and type. However, students whose like mathematics and physics and who have a higher technology readiness index score and those who were awarded scholarships are less likely to switch from science to non-STEM majors. Teaching approaches that create opportunities for students to engage in practical classroom activities and stimulate their curiosity in science and mathematics should be considered. Efforts to optimise learning experiences should therefore focus on creating a highly interactive teaching--learning environment as a cognitive-activation strategy for promoting students' interest and enjoyment of the subjects they are studying. Scholarship can also be an alternative to address the switching issue.