Our research program is intended to address the needs of a growing population of people with disabilities during the critical period of the transition to adulthood and to better understand the impact of the physical, social and attitudinal environment on participation in society and quality of life in young adults with cerebral palsy. Young people with disabilities represent an emerging group of citizens enjoying better health care, new communication technologies and societal attitudes allowing inclusion in all areas of living. They have both the right and the wish to fully participate in society. However, they continue to be disadvantaged in many domains and face numerous barriers such as fragmented health care beyond the age of adolescence, lack of integration of health, social, educational, and work related services, poor accessibility in their own homes and in the community, stigmatizing attitudes harmful not only to the individual but also to their supporting network. All result in isolation, increased vulnerability, and restricted involvement in life situations as compared to able-bodied peers. With lower employment rate and education level, the poverty rate for the disabled is 70% higher than the average. Our overall objective is to explore the determinants of a successful transition to adulthood in young people with cerebral palsy living in very different European regions in France and Germany. Cerebral palsy is studied as an exemplar of the disabled condition. We aim to identify enabling factors and barriers in the transition process in several life areas, focusing on environmental determinants and health care services amenable to interventions. Comparison with the general population will identify in what domains difficulties are the most prevalent. We will characterize the trajectories from childhood to young adulthood and determine the predictors of a successful young adulthood in the health, educational, professional and social fields in a longitudinal sample for which we have data from two previous data collections of young people with cerebral palsy.The main outcome is participation as defined by the International Classification of Functioning, Disability and Health (ICF) of the WHO (2001). It will be measured both as the quantity of participation as well as its subjective appraisal. The secondary outcome will be health status and quality of life, a multidimensional concept which includes subjective evaluations of both positive and negative aspects of life. Predictors will be the environmental factors (physical and social), social determinants and attitudes, health services, social services, and access to employment taking into account regional variation across sites.