ObjectivesZZThis study was conducted in order to explore the prevalence of suicidal behavior and the risk or protecting factors. In addition, childhood trauma, school violence, and social support were hypothesized to have an association with suicidal behavior.MethodsZZData were collected by self-report questionnaire from 1219 students selected from middle schools in Guri-city, Korea. The students were asked to complete self-questionnaires and sociodemographic variables were collected for identification of factors associated with suicidal behavior.ResultsZZThe prevalence of suicidal attempt was 1.1% (0.6%, 1.3%) from the total sample. Meaningful predictors of suicidal ideation were female, low socioeconomic status, low self-esteem, emotional abuse, neglect, delinquency, perpetration of school violence, family support, and friend support, in addition to the significant effect of depressive mood. In the case of suicidal attempt, female, low socioeconomic status, or delinquency showed a significant incremental effect, in addition to the explaining variance of depressive mood and suicidal ideation.ConclusionZZChildhood experience should be dealt with, and school violence should be controlled in order to modulate mood disturbance and pessimistic ideation, which can block the channel to suicidal attempt. In addition, development of strategies for management of depression and delinquency is needed for prevention of suicidal attempt.J Korean Neuropsychiatr Assoc 2014;53(4):228-236 KEY WORDSZZ Suicide · Suicidal ideation · Suicidal attempt · Childhood trauma · School violence.