Throughout the world, many adolescent reproductive health professionals, schools, clinics and other youth serving organizations have developed and implemented a wide variety of sex and STI/HIV education programs to reduce unintended pregnancy and STIs among young people. Some of these programs are based on a written curriculum and are implemented with groups of young people. These programs are particularly well designed to be implemented in schools, where they can potentially reach large numbers of youth. This paper summarizes the results of a review of the impact of sex, and STI/HIV education programs conducted for UNESCO in 2008-2009 (UNESCO, 2009).