Current policies limit access to sexual and reproductive health services for adolescents younger than 16 years in Jamaica. Using data from a national survey, we explored the relationship between age at sexual initiation and subsequent sexual risk behaviors in a random sample of 837 Jamaican adolescents and young adults aged 15-24 years. In the sample overall, 21.0% had not yet had sex. Among the 661 sexually active participants, the mean age at first sex was 14.7 years. High percentages of sexually active youth reported engaging in risk behaviors such as inconsistent condom use (58.8%), multiple sex partners (44.5%), and transactional sex (43.0%). Age of sexual initiation for males was unrelated to subsequent sexual risk behaviors. However, earlier sexual debut for females was associated with their number of partners during the preceding year. Findings underscore the potential benefits of access to sexual and reproductive education and services at earlier ages than current policies allow. Interventions before and during the period of sexual debut may reduce sexual risk for Jamaican adolescents and young adults.