Despite the high incidence of sexual assault, doubt about allegations is common. Previous research suggests that victims expressing positive or no emotion are perceived as less credible than those expressing negative emotions. However, little is known about which specific negative emotional expressions contribute to credibility in this context. In two studies (N = 623), participants read a date rape vignette. The alleged victim's statement was paired with a picture of a female person expressing either shame, sadness, or no emotion. Participants rated the credibility of her account and completed a measure of rape myth acceptance. Controlling for rape myth acceptance, allegations were perceived as more credible when accompanied by an expression of shame versus sadness (a negative, low arousal control condition). It is critical to be aware of the shame-credibility bias in this context to intervene and support those who have experienced sexual assault.