The empirical literature on the psychological impact of sexual assault on women and children is reviewed. The symptoms of adult female rape victims generally resembles Post-Traumatic Stress Disorder (PTSD). Immediately after the assault, rape victims show high levels of distress, which tends to gradually diminish during the following months and years. In contrast, children's reactions to sexual abuse does not as closely resemble PTSD. Even though sexual abuse is associated with negative long term adjustment, a substantial minority of child victims of sexual assault show little overt adjustment problems upon initial assessment. Factors related to the negative psychological impact of sexual assault are discussed.