Sexual assault and suicide are two serious public health concerns. Research has documented the relationship between sexual assault and suicidal thinking and attempts; however, limited research explores the more multifaceted relationships between posttraumatic stress reactions and suicidal ideation in college students through unsuccessful modulation of emotion. The authors hypothesized a mediation model where the relationship between sexual assault and suicidal ideation is mediated by dissociation and hostility. In total, 1,677 undergraduate students were administered modified versions of the Traumatic Life Events Questionnaire (TLEQ), Symptom Checklist–90–Revised (SCL-90-R), and Peritraumatic Dissociative Experiences Questionnaire (PDEQ). The results revealed both significant partial but equal mediators of hostility and dissociation. However, a portion of the direct effect between sexual assault and suicidal ideation remained unaccounted for by indirect effects. The current model supports previous work on dialectical behavior therapy that says either side of the dialectic between extreme expression and suppression of hostility increases the likelihood of suicidal thinking after sexual assault. With sexual assault survivors, practitioners should use strategies that emphasize both anger expression and healthy avoidance as a way to modulate emotion to potentially reduce suicidal thoughts. Future research should focus on different gender models, additional possible mediators such as alcohol use and guilt, and different forms of sexual assault. Limitations of the correlational, cross-sectional methodology are discussed.