Basic goal of this study was to determine if children who, according to the self-evaluation meet the criteria for the diagnosis of one of the three types of attention deficit/hyperactivity disorder (ADHD; predominantly hyperactive-impulsive type, predominantly inattentive type, combined type), differ and who are, according to the self-evaluation, suspected of having ADHD (who have 4 or 5 symptoms of ADHD) considering the level and the type of peer violence (verbal, physical, electronic), aggression (proactive, reactive) and peer victimization (verbal, physical, electronic) in regard to children who do not think that they have symptoms of ADHD. The participants were 501 pupils (50.7% boys and 49.3% girls) of forth, sixth and eighth grades from six elementary schools. Age ranged from 10-16 years and mean age of the pupils was 12.72 years (sd=1.62). The children completed the Reactive-Proactive Aggression Questionnaire (RPQ; Raine et al., 2006), the Peer Violence Among School Children Questionnaire (UNŠD; Velki, 2012) and the Hyperactivity-Impulsivity-Attention Scale (HIP; Vulić-Prtorić, 2006). It has been established that children who, according to the self-evaluation, meet criteria of the disorder and children suspected of developing the disorder exhibit higher level of aggression and peer violence in regard to children who feel that they do not have symptoms of ADHD, but such children are also victims of peer violence among children. Higher levels of violence and aggression were found in children with combined type and predominantly hyperactive-impulsive type of ADHD. It can be concluded that symptoms of hyperactivity and impulsivity pose a bigger issue for a child than symptoms of inattention, especially when it comes to peer violence and aggressive behaviour among children.