Purpose. To chart the 3-year course of health-related quality of life (HRQoL) of 9-13-year-old children with cerebral palsy (CP), and to determine its relationship with gross motor abilities and mental health. Methods. Children ( n 91; 58 boys, mean age 11 years, age ranging from 8 years and 6 months to 13 years and 8 months) and parents were assessed annually with the TNO-AZL questionnaires for children's health-related quality of life as a dependent variable, and the gross motor function measure for children with CP and the child behaviour check list as independent variables. Results. The children reported lower HRQoL compared with children in the general population, but reported a higher HRQoL than their parents. The HRQoL remained fairly stable over the 3 years, except for an increase in the autonomy domain. The HRQOL was moderately associated with gross motor abilities, and negatively associated with internalising mental health problems. Externalising problems were only negatively associated with parent-reported HRQoL. Conclusions. Children with CP are more resilient and positive about their HRQoL than their parents think they are. In general, mental health in children with CP appeared to be important in understanding their perceived QoL, in addition to the severity of the CP itself. © 2010 Informa UK Ltd.