To enhance understanding of factors that may improve students' STEM career participation, we explored Hong Kong secondary students' self-perceptions of STEM subjects and career interests using the STEM Semantic Survey and Career Interest Survey questionnaire. Results showed that most students thought technology was more appealing than science, mathematics, and engineering subjects. Science was the only subject in which male and female students showed similar attitudes. A gender gap was found in these students' career interests in STEM. Students held a neutral to mildly positive stance toward a career related to science, technology, and mathematics but had the least interest in a career related to engineering. Males showed more interest than females in careers related to all four subject areas. Results revealed a need to stimulate students' interest in STEM education and search for ways to make a connection between STEM subjects and future careers through STEM teaching in the classroom. More attention should be paid to encouraging girls to engage in STEM-related activities.