Introduction
Peer violence is a serious type of school violence that is associated with emotional and behavioral problems. 

Objective
To analyze violence between peers associated with students' social skills. 

Methods
We used a cross sectional survey nested in a cluster randomized controlled trial to evaluate peer violence among elementary school students and its association with prosocial behaviors and mental problems. Teachers answered an adapted version of the Revised Olweus Bully/Victim Questionnaire and the Brazilian adaptation of the Teacher Observation of Classroom Adaptation-Checklist (TOCA-C) scale for each student. Children completed a sociodemographic questionnaire. The participants were 1,152 5-14-year-old children from Brazilian public schools; 79.70% reported being involved in violent situations. 

Results
Children who had both committed and suffered violence were less likely to exhibit prosocial behaviors. Children who committed and suffered violence and those who only committed were more likely to experience concentration problems and disruptive behaviors. 

Discussion
This study suggests that peer violence is associated with lower prosocial behaviors and more behavioral problems. Thus, more specialized mental health care is required for children involved in peer violence, in addition to the possibility of implementing and maintaining programs to prevent and reduce violence and to develop prosocial behaviors in schools.