Abstract: This study aims to study the influence of childhood adversity on suicidal behavior in male prisoners. Including a random sample of 899 male prisoners (French National Mental Health Prison Survey, 2003), this paper studied suicidal ideations and suicide attempts using MINI criteria, and personality using Temperament and Character Inventory. Risk factors of suicidality were examined, and structural equations studied the influence of childhood trauma on suicidality, mediated by personality dimensions. The prisoners reported high levels of childhood adversity. More than a third reported recent suicidal ideations. Childhood adversity and dimensions of personality were associated with suicidality. Structural equations showed that childhood adversity was positively associated with suicidality, mediated by poor dimensions of character (affective stability, self-cooperativeness, and self-transcendence). In conclusion, these results confirm the importance of screening and treatment of childhood trauma among male prisoners. They suggest the importance to study dimensions of personality and tailor treatment to specific needs.