This study shows longitudinal predictors of involvement in different bullying roles, including mental health, individual, family, peer and school predictors. The analyses were based on a longitudinal prospective study with 916 students followed up from ages 7 to 17 with 7 waves of data. Participants were selected through random sampling and were enrolled in 56 schools. Predictors were measured from ages 7 to 11 and involvement in bullying roles and trajectories from ages 11 to 17. Predictors of bullying perpetration were gender, substance use, truancy, ADHD, moral neutralization, self-control, parental monitoring, corporal punishment, liking school, and bonding with the teacher and classmates. Predictors of victimization were gender, substance use, truancy, internalizing problems, self-control, ADHD, bonding to classmates, and social activities. Predictors of bully/victims were gender, divorced parents, substance use, internalizing problems, ADHD, sensation seeking, moral neutralization, selfcontrol, corporal punishment, parental monitoring, liking school, bonding to classmates, and social activities. Truancy was a risk factor for perpetration mostly in girls; low self-control was a risk factor for perpetration especially in boys. Truant children with high classmates bonding were at high risk of perpetration. Low parental monitoring was a risk factor for perpetration in children who did not like school. Low social activities with peers were a risk factor for victimization in boys and substance use was a risk factor for victimization especially in children with low self-control. High classmates bonding was protective against victimization in non-truant children and against being a bully/victim in children with high sensation seeking. Early interventions focused on risk and protective factors could possibly protect children from bullying. Keywords Bullying. Longitudinal study. Childhood risk and protective factors School bullying is a serious public health problem, defined as long-term, frequent, and intentionally harmful aggressive behavior among students. In bullying situations, perpetrators inflict harm on victims who find it difficult to defend themselves (Smith and Brain 2000). Different bullying roles such as victims, perpetrators, and bully/victims have been described. Victimization (being bullied) is related to long-term health issues such as psychosomatic problems (Gini and Pozzoli 2013; Gini et al. 2014b) and depression later in life (Averdijk et al. 2011; Sourander et al. 2016; Ttofi et al. 2011b). School bullies have a high probability of later offending (Ttofi et al. 2011a) and drug use (Ttofi et al. 2016). Consequences for bully/victims include suicidal thoughts, behavior, and weapon carrying (Zych et al. 2015). Also, involvement in any bullying role is related to suicidal thoughts and behavior (Holt et al. 2015), weapon carrying (Valdebenito et al. 2017), and other adult psychiatric outcomes (Copeland et al. 2013). Thus, understanding and reducing school bullying are urgently needed, and protecting