The objective of this study was to evaluate quantitatively through meta analysis the effectiveness of child sexual-abuse prevention programs conducted over the past 10 years. Eighteen controlled studies evaluating such programs were coded for salient features and study outcomes and were then described using the common scale of effect size. An overall effect size was calculated, using each of the 18 studies as a single data point. The results were striking. In comparing the effects of prevention programs to control group performances, a mean effect size of 0.57 was calculated, which indicated a moderate effect on posttest knowledge. Follow-up retention scores across studies also reported a medium effect size of 0.47 from 2 weeks to 1 year following training. Moreover, preschool-age children demonstrated large effect sizes on posttest and follow-up scores, while school-age children demonstrated moderate effects. The method of program presentation was found to have differential effects on student performance, with active, behavioral teaching methods more effective. The implication of this meta analysis is that a brief training program appears to be an effective, economical method of imparting sexual-abuse prevention strategies to children. Contains three tables, two figures, and 26 references. (Author/SLD)