This special edition of Global Studies of Childhood reports on the global research currently under way to replicate the original seminal work by Mayer Hillman on children's independent mobility that was conducted in the United Kingdom in the early 1970s, and which was replicated in the United Kingdom and Germany in the 1990s (Hillman et al, 1990) and is now being revisited in 20 culturally diverse countries. The opportunity for children to move freely in the environment without an accompanying adult is defined in the literature as children's independent mobility or CIM (Hillman et al, 1990; Tranter & Whitelegg 1994). CIM is measured in terms of spatial range or roaming range, and this measure can be determined by parents or caregivers in terms of the boundaries they set or through a negotiation between children, parents or caregivers and even the community. Children's spatial range may change according to a child's maturation, health and cultural background, social and cultural influences in parenting styles and boundary making (often influenced by issues of safety and risk), physical attributes of the environment and differences in the role of the community as ‘loco parentis' and on the role children are purported to have in terms of being socially determinant. The research project that the four countries reported on in this special issue, namely Australia, Japan, South Africa and Tanzania, have participated in had two main aims. The first aim was to provide a national and international comparison of children's and parents' views of the independent mobility of children aged 7–15 years from a variety of social and cultural contexts by contributing to and building on the original seminal study (Hillman et al, 1990). It also provided the opportunity for general historical comparisons with original research that was collected using the same or similar questionnaires over the past 20 years. In the article written by Rudner & Malone on CIM in Australia, for example, a comparison is being made with the work of Tranter, from the early 1990s, with schools in similar localities (Tranter & Whitelegg 1994). Finally, the focus was to explore how CIM varies internationally, and to identify the factors affecting CIM and the implications this may have for children's lives. This final aim is particularly important as most of the research on CIM has been conducted in western industrialised nations (for instance, two recent publications by Freeman & Tranter [2011] and Fyhri et al [2011] report almost exclusively on studies in Europe, the United Kingdom, Australia and New Zealand) and therefore provides a very limited perspective of what is prioritised as the important debates, key trends and issues being purported globally around CIM.