Background <p>Women remain under-represented in science, technology, engineering, and mathematics (STEM) careers worldwide, despite decades of effort to narrow the gender gap. Universities are expected to serve as gender equalizers in STEM education; however, it is still unclear whether university-led STEM programs provide women and men with equal access and comparable outcomes. Although prior research has examined factors shaping students’ STEM career commitment, limited attention has been given to gender differences in how these factors operate or to the mechanisms underlying such differences. Therefore, grounded in Social Cognitive Career Theory, this study investigates gender differences in the effects of university-led STEM program factors (course resources, research opportunities, mentoring quality, and peer interactions) on undergraduates’ STEM career commitment through the mediating roles of STEM professional self-efficacy and perceptions of STEM professionals.</p> Results <p>A nationwide survey was conducted with 19,108 undergraduate students from 39 leading universities across China. Analyses employing <i>t</i> tests, regression models, and multi-group structural equation modeling yielded three principal findings. First, students who participated in the university-led STEM program exhibited smaller gender disparities in STEM career commitment than their non-participating peers. Second, the influence of program-related factors on STEM career commitment differed significantly between men and women students. Third, gender differences emerged in the mediating roles of STEM professional self-efficacy and perceptions of STEM professionals in linking program-related factors to STEM career commitment.</p> Conclusions <p>The findings underscore the pivotal role of university-led STEM program factors in fostering STEM career commitment among undergraduates while also revealing distinct gender-specific pathways. Notably, despite the under-representation of women students in the university-led STEM program, their levels of STEM career commitment were comparable to those of their men counterparts. Course resources and research opportunities were particularly beneficial for women students, whereas peer interactions exerted a stronger influence on men students. Mentoring quality emerged as equally valuable for both groups. For women students, STEM career commitment was more strongly shaped by course resources and research opportunities through the mediating effects of STEM professional self-efficacy and perceptions of STEM professionals. Conversely, men students’ STEM career commitment was more strongly influenced by peer interactions via their perceptions of STEM professionals. Overall, the results suggest that thoughtfully structured university-led STEM programs can act as powerful gender equalizers, promoting equitable pathways into STEM careers and contributing to the reduction of gender disparities.</p>