The objective of this study was to describe skeletal maturation in relation to chronological age in children with cerebral palsy (CP) aged 9 to 16 years, and to analyze the relationship between skeletal maturation and motor functioning. The skeletal age of 100 children with CP (37 females, 63 males; age 9, 11, or 13 y; 73 ambulant, 27 non-ambulant) was determined over a period of 3 years based on X-rays of the hand (Greulich and Pyle technique). Motor functioning was measured with the Gross Motor Function Measure-66. The skeletal age of females with CP was significantly higher than their chronological age, but this did not apply to males. Longitudinal analysis showed no difference in the course of skeletal age in relation to chronological age over a 3-year period for sex or for level of ambulation. No association was found between changes in skeletal age and changes in gross motor function over the 3-year period. Skeletal age during (pre-)puberty in females with CP is advanced in relation to chronological age. No evidence was found that children with CP are at risk for deterioration in gross motor function as a result of skeletal maturation during puberty.