Unsafe sexual behavior among teenagers and young adults would have critical personal impact as well as social and economic burden to the society. The major negative consequences of unsafe sexual behavior were the unwanted teenage pregnancies and sexually transmitted diseases (STDs). In recent decade, different types of adolescent sex education programs were developed in order to safeguard adolescents’ health and relieve the public health burden resulting from the negative consequences of unintended teenage pregnancy and STDs; and different studies were published to evaluate the effectiveness of the adolescent sex education programs in the Asian countries. In this systematic review, 15 studies evaluating the effectiveness of adolescent sex education programs from China, Hong Kong, Japan, Korea, Mongolia, Thailand and Vietnam, were identified. The adolescent sex education program was an effective approach for increasing the knowledge towards HIV/AIDS; some of them were also beneficial on improving the refusal skills towards sexual appeal or knowledge, efficacy or attitude in condom use. Nevertheless, due to the difference of study designs, sample size and outcome variables across studies, it is difficult to give an overall result in this review. i / published_or_final_version / Public Health / Master / Master of Public Health