PURPOSE: To investigate the extent to which selected individual, family and environmental variables were associated with participation of children who have cerebral palsy in activities outside school. METHODS: Data were gathered through a population-based survey of 114 children born in 1994 or 1995 in Victoria, Australia. Participation was measured using the Children's Assessment of Participation and Enjoyment. Selected independent variables were classified as related to the child, family or environment. Linear regression analysis was used to identify variables associated with participation in informal (activities that require little planning) and formal (those with structure and leaders) activities. RESULTS: Participation in informal activities tended to be greater in children who preferred informal activities and who had higher manual ability (adjusted R(2) = 36.3%). Girls and those with better gross motor function also tended to participate in more activities. The explanatory power of the regression model for participation in formal activities was limited (adjusted R(2) = 4.2%). CONCLUSION: Knowing a child's activity preferences is critical to intervention planning. Being exposed to a range of activities within supportive environments may provide the opportunity to develop preferences, especially in activities where children with cerebral palsy have reduced participation, such as in physical activities.