Objectives: To describe psychological symptoms in 8-12-year-old children with cerebral palsy; to investigate predictors of these symptoms and their impact on the child and family. Design: A cross-sectional multi-centre survey. Participants: Eight hundred and eighteen children with cerebral palsy, aged 8-12 years, identified from population-based registers of cerebral palsy in eight European regions and from multiple sources in one further region. Main outcome measures: The Strengths and Difficulties Questionnaire (SDQ)[superscript P4-16] and the Total Difficulties Score (TDS) dichotomised into normal/borderline (TDS less than or equal to 16) versus abnormal (TDS greater than 16). Statistical analysis: Multilevel, multivariable logistic regression to relate the presence of psychological symptoms to child and family characteristics. Results: About a quarter of the children had TDS greater than 16 indicating significant psychological symptoms, most commonly in the domain Peer Problems. Better gross motor function, poorer intellect, more pain, having a disabled or ill sibling and living in a town were independently associated with TDS greater than 16. The risk of TDS greater than 16 was odds ratio (OR) = 0.2 (95% CI: 0.1 to 0.3) comparing children with the most and least severe functional limitations; OR = 3.2 (95% CI: 2.1 to 4.8) comparing children with IQ less than 70 and others; OR = 2.7 (95% CI: 1.5 to 4.6) comparing children in severe pain and others; OR = 2.7 (95% CI:1.6 to 4.6) comparing children with another disabled sibling or OR = 1.8 (95% CI: 1.2 to 2.8) no siblings and others; OR = 1.8 (95% CI: 1.1 to 2.8) comparing children resident in a town and others. Among parents who reported their child to have psychological problems, 95% said they had lasted over a year, 37% said they distressed their child and 42% said they burdened the family at least "quite a lot". Conclusions: A significant proportion of children with cerebral palsy have psychological symptoms or social impairment sufficiently severe to warrant referral to specialist services. Care must be taken in the assessment and management of children with cerebral palsy to ensure psychological problems are not overlooked and potentially preventable risk factors like pain are treated effectively. The validity of the SDQ for children with severe disability warrants further assessment.