University students are often victims of sexual assault (SA) with a wide range of severity, but they are the least likely to disclose the assault or to take any concrete (legal) steps against the perpetrator. Prior work reported 13 main factors that influence university students' choice of reaction post-assault: (a) Fear of personal consequences, (b) distrust in authorities, (c) downplay of assault severity, (d) psychological factors, (e) situational factors, (f) lack of evidence, (g) emotional factors, (h) fear of interpersonal consequences, (i) social factors, (j) giving a benefit of doubt, (k) seeking justice, (l) needing support, and (m) presence of witnesses. In this experimental study, we included a student sample pre-screened not to have a history of SA (N = 419), and we provided them with a vignette. Vignettes were either neutral (control condition, n = 32) or manipulated to present each of listed factors (13 conditions, 26 < n(s) > 33). Students were randomly assigned to 1 of 14 conditions in total and were asked to imagine being a protagonist who was assaulted and to rate the likelihood of 8 different post-SA reactions (tell friends, tell family, confront the person, report, police report, do nothing, try to forget, and [falsely] deny). We investigated to see which of the 13 factors had the most impact on each of the reactions. Overall, our results indicate that, when comparing the manipulation groups to the neutral condition, social factors (e.g., religious family, stigma) have the highest impact on students' decision-making post-assault. Social factors increase the likelihood of all passive reactions (e.g., false denial, contrast = 1.82, p < .001) and decrease the odds of taking pro-active actions (e.g., making the report, contrast = -0.96, p = .002). The implications and the limitations of this study are discussed.