This study presents the prevalence of symptoms of Posttraumatic Stress Disorder (PTSD) in 500 schoolchildren (6-13 years old) in São Gonçalo, Rio de Janeiro. It also investigates the association between PTSD, violence and other adverse events in the lives of these children. The multi-stage cluster sampling strategy involved three selection stages. Parents were interviewed about their children's behavior. The instrument used to screen symptoms of PTSD was the Child Behavior Checklist-Posttraumatic Stress Disorder Scale (CBCL-PTSD). Conflict Tactics Scales (CTS) were applied to evaluate family violence and other scales to investigate the socioeconomic profile, familiar relationship, characteristics and adverse events in the lives of the children. Multivariate analysis was performed using a hierarchical model with a significance level of 5%. The prevalence of clinical symptoms of PTSD was of 6.5%. The multivariate analysis suggested an explanation model of PTSD characterized by 18 variables, such as the child's characteristics; specific life events; family violence; and other family factors. The results reveal that it is necessary to work with the child in particularly difficult moments of his/her life in order to prevent or minimize the impact of adverse events on their mental and social functioning.