Purpose: For the current article an examination was done as to whether engaging in sexual intercourse before or during adolescencehas a negative impact on the suicidal behaviors of suicide ideation, suicide attempt, and suicide lethality and whether the impact variesaccording to the context of sexual intercourse and/or gender. Methods: Adolescents who experienced casual sex and romantic sexwere compared to adolescents who retained their virginity. Data was from samples drawn from the three waves (2010~2012) of the KoreaYouth Risk Behavior Web-Based Survey. Logistic models were used to adjust for a wide array of confounding variables. Results: Anytype of sexual intercourse increases risk of all suicidal behaviors. Sexual intercourse in a romantic relationship exhibits enhanced risk ofsuicidal behaviors compared to casual sex. Adjusting for experience of sexual violence, however, decreases risk of romantic sex substantially,turning some estimates statistically insignificant. In addition, risks for suicide lethality are greater for girls than boys. Conclusion:Romantic sex put adolescents at higher risk for suicidal behaviors than casual sex owing to prevalent sexual violence in the relationships. Girls suffer more substantively adverse outcomes than boys. These results suggest that adolescents will benefit from comprehensiveeducation on sexuality and sexual behaviors regarding how to form and maintain a romantic relationship that is characterized bypersonal integrity and mutual respect. It is also important to help victims of sexual violence recover from traumatic events by providingemotional support and effective counseling.