The Children’s Sport Participation and Physical Activity study (CSPPA) was funded by the Irish Sports Council. It was a unique multi-centre study undertaken by Dublin City University, University of Limerick and University College Cork. It brought together expertise from physical education, sport and coaching studies and physical activity for health. The purpose of the study was to i) provide a national database of physical activity, physical education and sport participation levels of children and youth in Ireland, ii) assess indices of health and fitness in a sub-sample of the target population, iii) collect and analyse information on the factors influencing participation and iv) provide insight into issues surrounding volunteering in youth sports and activity clubs. The information collected will provide guidance to the development of policy in the areas of health, sport, education, transport and the environment all of which have important roles to play in getting Irish children more active more often. CSPPA was a cross-sectional study that used self-report surveys, objective measures of physical activity and qualitative interviews to assess participation in physical activity, physical education, extra-curricular and extra-school sport among 10-18 year olds. It was designed as a follow-up to the “School Children and Sport in Ireland” study published by the Economic and Social Research Institute (ESRI) in 2005 (1). Research methods were replicated where possible with the addition of certain elements. These included a redesign of the original questionnaire and the use of motion sensors called accelerometers. Basic physical health measures were also collected to examine the relation between physical activity levels and health. Pupils’ opinions, attitudes and views on the factors they deemed important in influencing their involvement in, or avoidance of, physical activity, physical education and sport were assessed through focus group interviews. The results of the focus group study are presented in a separate report. Finally, school administrators and volunteers responsible for providing sporting opportunities to 10-18 year olds were surveyed and a sub-sample were interviewed in order to gain an understanding of their motivations, needs and capacities. The results of the volunteers’ study are presented in a separate report.