Disgust sensitivity and feelings of mental contamination have both been independently linked to posttraumatic stress symptoms following sexual assault. Theory suggests that feelings of mental contamination may arise, at least in part, as a result of interpreting feelings of disgust experienced in relation to sexual assault to mean that one has been contaminated or tainted by the experience. This study involved an initial test of this model by examining relations among disgust sensitivity, feelings of mental contamination, and posttraumatic stress symptom severity among a sample of female sexual assault victims. Results suggested that one mechanism through which disgust sensitivity might relate to posttraumatic stress symptom severity is through its association with increased feelings of mental contamination. These findings highlight the importance of assessing feelings of disgust and mental contamination among victims of sexual assault, and the need for future research to elucidate the nature of these relations with posttraumatic stress.