This paper describes an investigation of the phenomenon of mental pollution in a sample of 50 female victims of sexual assault. Feelings of mental pollution were assessed using an interview and a questionnaire. An experimental procedure was employed to determine if feelings of dirtiness and the urge to wash could be provoked by deliberate attention to the assault memory. Thirty (60%) of the 50 participants reported some feelings of mental pollution subsequent to the assault, and feelings of mental pollution were related to post-assault washing behaviour. Deliberate recall of the assault resulted in stronger feelings of dirtiness and the urge to wash than did deliberate attention to a pleasant memory or scene. Nine women reported washing their hands in response to deliberate recall of the assault. These findings suggest that feelings of mental pollution may be prominent in victims of sexual assault.