This paper synthesizes 35 evaluations of specific school-based programs designed to reduce sexual risk-taking behavior, including sex and HIV education programs, school-based health centers, and school condom-availability programs. This paper summarizes the effects of those programs on several sexual and contraceptive behaviors. Although the studies have several limitations that restrict any conclusions, the evidence suggests that a few programs have produced credible evidence that they have reduced sexual risk-taking behavior by delaying the onset of intercourse, by reducing the frequency of intercourse, by reducing the number of sexual partners, or by increasing the use of condoms or other forms of contraception. The majority of studies, however, found no statistically significant impact on risk-taking behaviors. Of considerable importance in this controversial field, none of the studies found statistically significant results indicating that any of the programs increased any measure of sexual activity, as is often feared.