Behavioural problems in childhood are common, with significant and wide-ranging implications for individuals, families and the community. There is some evidence that sensory processing difficulties are associated with behavioural problems in children with disabilities such as autism spectrum disorders (ASDs) and attention-deficit/hyperactivity disorder (ADHD). However, there has been minimal research into the association between sensory processing difficulties and behavioural problems in the absence of these disorders. The aim of this investigation was to determine the prevalence of sensory processing difficulties in children aged 5 to 9 who have been identified as at risk of developing conduct disorder, and to examine the relationship between sensory processing difficulties and behavioural problems. Participants were children aged 5 to 9 selected to participate in an early intervention program for children at risk of developing conduct disorder. Behaviour problems were assessed using the Eyberg Child Behaviour Inventory (ECBI; Eyberg and Robinson 1983) and the Strengths and Difficulties Questionnaire (SDQ; Goodman 1997). Sensory processing was assessed using the parent-reported Short Sensory Profile (SSP; McIntosh et al. 1999). Sensory processing difficulties were identified in 55.2%, which is higher than the estimated prevalence in the community (5.3-13.7%). Significant correlations were found between sensory processing difficulties and severity of behavioural problems. Using multiple regression analysis, sensory processing difficulties made a significant unique contribution to behavioural problems, and contributed more to the model than did other variables-language difficulties and socio-economic status. Notwithstanding the need for further research, these findings suggest that sensory processing should be considered in the assessment and management of children with behaviour problems.