Background: Cerebral palsy (CP) is a well-recognized neurodevelopmental condition persisting through the lifespan. In many individuals with CP, motor disorders are accompanied by other disturbances, including emotional and behavioural problems. Little is known on the course of such problems, also in relation to possible exacerbating or mitigating factors. Aims of this study were to test whether parental stress and support, apart from the severity of CP of the child, played a significant role in the course of behaviour problems. Method: The participants aged 9, 11 and 13 were assessed (baseline) and followed up after 1, 2 and 3 years. Situational and relational sources of support and stress for the primary caregiver were rated with a questionnaire: (CBCL), behaviour problems with the Child Behaviour Checklist. Physicians rated motor ability using the Gross Motor Function Classification System. Results: Behaviour problems of children with CP started significantly higher than in the general population, but diminished over the 3-year period. Older children showed less problems overall, and girls showed less externalizing problems than boys. Children with the most severe CP had more externalizing problems; effects on internalizing problems were not significant. Across time, an excess of stress vs. support related to parents' socio-economic and living situation and to parents' social relationships was positively related to total behaviour problems, internalizing and externalizing behaviours of children. Conclusions: Levels of behaviour problems are elevated but diminish during adolescence for children with CP. Severity of CP plays a role as well as the family context in terms of the stress and support that caregivers experience. © 2010 Blackwell Publishing Ltd.