Nearly one third of Nigeria's total population of 148.1 million is between the ages of 10 and 24. Nigerian adolescents' sizeable share of the population makes them integral to the country's social, political and economic development. Nigeria's development is compromised by the sexual and reproductive health issues afflicting its youth. Lack of sexual health information and services make young people vulnerable to sexually transmitted infections (STIs) and unintended pregnancy. However, many organizations are working to improve adolescent reproductive and sexual health through advocacy and prevention programming. This paper presents the facts about the reproductive and sexual health of Nigerian youth. These are: (1) Contraceptive use is low and youth underestimate risks of unprotected sex; (2) Young women are at risk of unintended pregnancy, often resulting in unsafe abortion; (3) Youth are at risk of HIV and lack knowledge about STIs, including HIV; (4) Attitudes towards traditional gender roles lead to unsafe sexual practices; and (5) Civil society organizations are implementing important advocacy and prevention initiatives.