The aim of this study was to investigate the participation of children with cerebral palsy (CP) in activities outside school and to compare their participation with a large representative sample of children. A population-based survey was conducted of children with CP born in Victoria, Australia in 1994 and 1995. Of 219 living children identified, 114 (52.1%) returned completed surveys. The children (65 males, 49 females) were aged between 10 years 9 months and 12 years 9 months (mean age 11y 9mo, SD 6mo). Thirty-eight per cent had hemiplegia, 23% diplegia, 4% triplegia, 34% quadriplegia, and 1% was of unknown topography. Distribution according to the Gross Motor Function Classification System (GMFCS) was 22.8% Level I, 36% Level II, 10.5% Level III, 8.8% Level IV, and 21.9% Level V. Distribution according to the Manual Ability Classification System (MACS) was: 19.3% Level I, 38.6% Level II, 14.0% Level III, 8.8% Level IV, and 19.3% Level V. Participation was measured using the Children's Assessment of Participation and Enjoyment. Participation in selected sport, cultural, and quiet leisure activities was compared with population-based data for 11-year-olds from the Australian Bureau of Statistics. Children with CP undertook a median of 26.5 activities (interquartile range 10) in 4 months which were commonly informal rather than formal. Intensity of participation was low. Diversity and intensity of participation was similar for children in each level of the MACS and the GMFCS, except for participants in Level V. More children with CP participated in organized sports (p less than 0.001) compared with other Australian children, although with lower frequency (p less than 0.001). Participation diversity and level of intensity of Australian children with CP were similar to those reported in a Canadian study.