This research aimed to analyse the personal characteristics and parental styles of bullies and delinquents, and to establish which factors were related to the bully/delinquent group and which were related to only bullies or only delinquents. A self-report questionnaire on bullying and delinquency was completed by 113 girls and 125 boys aged 11ยฑ14 in a middle school in Rome. Bullying and delinquency were more common among boys than among girls. Bullying did not vary signiยฎcantly with age, but delinquency increased with age. Bullying and delinquency were especially related for boys and for older students. Only bullies were younger, while only delinquents were older, suggesting that bullying might be an early stage on a developmental sequence leading to delinquency. Only bullies and only delinquents had dierent parenting correlates; only bullies had authoritarian parents and disagreed with their parents, whereas only delinquents had conยฏictual and low supportive parents. This suggested that bullying and delinquency are not merely dierent behavioural manifestations of the same underlying construct. Parent training interventions might prevent both bullying and delinquency.