Purpose: Suicide has been considered a large public health concern in recent years because suicide mortality has been increasing rapidly. This study was done to investigate the prevalence and risk factors of a suicide attempt among adolescents in South Korea. Methods: The data of the 2006 Youth Health Risk Behavior web-based Survey collected by the Korean Center for Disease Control was analyzed using logistic regression for this study. Results: The prevalence of a suicide attempt was 5.2% in South Korea. The risk factors of a suicide attempt were suicidal ideation (odds 31.83), depression (odds 7.98), drug use (odds 4.67), currently smoking (odds 3.19), feeling unhappiness (odds 2.77), stress (odds 2.60), currently drinking alcohol (odds 2.39), sexual activity (odds 2.33), living with neither parent (odds 2.24), initial alcohol drinking by age 9 (odds 1.80), health status (odds 2.15), skipped breakfast (odds 1.75), disease (odds 1.65), and school records (odds 1.22). Conclusion: Suicide screening and prevention programs should be developed, considering these risk factors. Suicide prevention programs should be applied to the at risk population prior to a suicide attempt.