Background For several decades. researchers and clinicians have been aware of an increased prevalence of psychiatric disorder in children with intellectual disability. However, there are few research studies Exploring this issue. Methods The parents of 123 children attending schools for children with 'severe learning difficulties' completed the Developmental Behaviour Checklist (DBC) in order to identify those children with clinically significant behavioural and emotional problems. Comparisons were made with norms for the DBC and a range of child variables were investigated as possible correlates of disorder. Results Some 50.4% of the children scored above the cut-off on the DBC for psychiatric disorder. The child's severity of physical disability was related most strongly to parental ratings of behavioural and emotional problems. There were also effects for the child's age and the absence of Down's syndrome. Conclusions The present study confirms previous research findings of a high prevalence of behavioural and emotional difficulties amongst children with intellectual disability, and identifies a number of correlates of disorder which require further investigation.