This article reviews numerous studies of parent-adolescent communication about sexuality and 30 studies of sexuality and HIV education programs. Although parent-adolescent communication about sexuality has increased during the last few decades, both the occurrence and the quality of this communication could still be greatly improved. There does not exist a clear simple relationship between greater parent-adolescent communication and less adolescent risk-taking behavior, but both adults and youth believe it is important anyway. Sexuality and HIV education programs do not increase any measure of sexual activity, but some of them with ten common characteristics do reduce sexual risk-taking, either by delaying or reducing sexual behavior or increasing condom use. Thus, these programs can be an effective component in a larger initiative to reduce HIV, other STDs, and unplanned pregnancy in adolescence.