This research examines the impact of a 2-day scientific conference on high school students' confidence in attending university and interest in postsecondary science, technology, engineering, and mathematics (STEM) programs. Specifically, this study investigates (1) whether exposure to STEM in grades 10 and 11 significantly increases self-reported confidence in attending university; (2) whether conference participation increases students' interest in pursuing STEM programs; and (3) whether the impact of the conference on confidence and interest may differ for first-generation students, female students, and grade 10 versus grade 11 students. One hundred and eighty-four high school students in Ontario Canada (28.3% male) completed a self-report survey examining perceptions of the conference, self-confidence in attending university, and interest in STEM. Results demonstrated that students' confidence in attending university increased after participating in the conference and that the majority of students reported that the conference increased their interest in science and math. No sex or grade differences emerged, although there were trend-level associations regarding confidence levels and interest in STEM for first-generation students relative to their cohort. University-based STEM initiatives may be an effective way to increase high school students' interest in the sciences and promote student enrolment in postsecondary STEM programs.