The prevalence of direct and relational bullying and their differential relationship to behaviour problems in young primary school children was investigated. Individual interviews were conducted with 1982 children aged 6–9 years (mean age 7.6 years) and 1639 parents completed the Strength and Difficulties Questionnaire regarding behaviour problems of their children. Of the 1639 children with both data sets, 4.3% were direct bullies, 39.8% victims, and 10.2% both bullied and were victimised frequently (bully/victims). The rates for relational bullying were 1.1% bullies, 37.9% victims, and 5.9% bully/victims. All children involved in direct bullying had significantly increased total behaviour problems, hyperactivity, conduct problems, and peer problem scores, and lower prosocial behaviour scores compared to those not involved in bullying (neutrals). Findings were similar for relational bullying involvement and behaviour problems for bully/victims and victims but less pronounced. Relational bullies had the lowest behaviour problem scores while being rated the least prosocially inclined children, consistent with the concept of a cool manipulator. Overall, direct bully/victims and children who were involved in both direct and relational bullying behaviour had the highest rates of behaviour problems. No relationship between victimisation and increased emotional problems were found. Those involved in bullying behaviour who show externalising and hyperactivity problems in primary school may be at increased risk for persistent conduct problems. Different interventions may be needed for those involved in relational bullying only, both direct and relational bullying, and those with additional behaviour problems.