Young children (ages 4 and 5) and school-aged children (6 to 10) from a day-care center were randomly assigned to a sexual abuse prevention training group and a wait-list control group. Children in the prevention training group were exposed to a three-hour program teaching common sexual abuse prevention concepts (e.g., the difference between OK and not-OK touches). Children in both groups were given a structured interview before and after the prevention group received training. Results of a repeated measures multivariate analysis of variance indicate that children in the prevention training group significantly increased their knowledge of prevention concepts while children in the control group did not. Older children learned more than younger children. Both younger and older children had greater difficulty learning prevention concepts of an abstract nature than concepts of a specific nature.