Socially sustainable development from the point of view of children means a long term perspective on time, backwards as well as forward and with focus on the relationships between individuals and their physical environments in the context of socio-cultural processes. The slow long-term changes in children’s gradual environmental understanding unfold in interaction with parents, family and their broader social and cultural belonging, suggesting the importance of intergenerational exchange, as well as children’s own interactions with and experiences of physical environment (Görlitz 1998). That these long-term socio-cultural and psychological changes are slow, does not mean that they don’t change, lending a dynamic character to sustainable development (Reed-Danahay 1996). The acceleration of urban development today affects children differently due to age, gender, social and cultural background as well as local environment (O’Brien et al 2000; Chawla 2002; Depeau 2003). Efforts recognizing differences in children’s environmental experiences and evaluations are important when communicating with children and their parents and a condition for successful participation in urban planning projects (Hart 1997; Tonucci & Rissotto 2001; Horelli&Prezza 2004; Simkins 2005). Making children participate in environmental planning processes is one way to give the term “child-friendly environments” substance (www.childfriendlycities.org). Another way is to analyze statements on child-friendly environments. This paper will analyze from the perspective of access to and use of the local environment well as socio-cultural background, statements expressing what 12-year old children in urban and suburban Stockholm, Sweden, generally great users of outdoor environment, value as child-friendly environments. Notions of environmental child-friendliness by parents and other adults concerned with the children in their everyday life will be presented, analyzed and compared to those by the children, in order to show children’s dependence on adults in forming their notions about environment but also to stress the fact that environment is understood and valued differently by children and by adults but important in their interaction with each other (Bjurman 1981; Sebba 1991; Lidén 1997; Karsten 1998, 2005; Cele 2005; Nordström 2005).