The purpose of this study was to evaluate gender differences in determinants of bystander intervention (BI) participation among undergraduate students using the Reasoned Action Approach (RAA). Students (n = 291) were recruited via an online survey disseminated in general education courses at two US universities. The survey evaluated intentions, attitudes, perceived norms, and perceived behavioral control toward participating in BI. Two linear regression models (man/woman) were used to understand how constructs of RAA regressed on intentions. Students, 18-24 years old, were mostly women (60.1%) and lowerclassmen (80.4%). While both models were significant, the model better predicted intentions among women (adjusted R[superscript 2] = 0.598) compared to men (adjusted R[superscript 2] = 0.479). Women had significantly higher intentions, attitudes, and perceived behavioral control to engage in BI compared to men (p < 0.05). Results show that men and women have different views on BI, and ways to promote BI may be better if they were tailored by gender. This provides insight into the role gender plays in BI to prevent sexual assault and could enhance health education approaches on campuses.