ABSTRACT: Study Design. Epidemiological total population study based on a prospective follow-up CP registry.Objective. To describe the prevalence of scoliosis in a total population of children with CP, to analyse the relation between scoliosis, gross motor function and CP subtype, and to describe the age at diagnosis of scoliosis.Summary of Background Data. Children with cerebral palsy (CP) have an increased risk of developing scoliosis. The reported incidence varies, partly due to different definitions and study groups. Knowledge of the prevalence and characteristics of scoliosis in an unselected group of children with different CP types and levels of function is important for health care planning and for analysing the risk in an individual child.Methods. A total population of 666 children with CP, aged 4-18 years 1 January 2008, followed with annual examinations in a healthcare program was analysed. Gross motor function (GMFCS level), CP subtype, age at clinical diagnosis of scoliosis, and the Cobb angle at the first radiographic examination were registered.Results. Of the 666 children 116 (17%) had mild and a further 76 (11%) had moderate or severe scoliosis based on clinical examination. Radiographic examination showed a Cobb angle >10 degrees in 54 (8%) children and >20 degrees in 45 (7%) children. The risk of developing scoliosis increased with GMFCS level and age. In most children the scoliosis was diagnosed after 8 years of age. Children in GMFCS level IV or V had a 50% risk of having moderate or severe scoliosis by the age of 18, while children in GMFCS level I or II had almost no risk.Conclusions. The incidence of scoliosis increased with GMFCS level and age. Observed variations related to CP subtype were confounded by GMFCS, reflecting the different distribution of GMFCS levels in the subtypes. Follow-up programs for early detection of scoliosis should be based on the child's GMFCS level and age.