Background: Estimates suggest that over a million children per year are deprived of their liberty across the world. Little is known about the types, ethos or distribution of secure beds in which they are detained. Aim: This study aims to provide quantitative data with background information, to explore similarities and differences across jurisdictions, and to inform critical inquiry into key concepts and practices. Methods: Data was obtained using an opportunistic sample of affluent countries, derived from an emerging academic/practice network of senior professionals. Depending on jurisdiction, data was already in the public domain or specifically requested. Data requests were related to the nature and size of health, welfare and criminal justice elements of secure beds and recent occupancy. Key professionals working in child secure settings, within jurisdictions, provided commentary on local approaches. Results: Data was incomplete but allowed for comparisons between 10 jurisdictions. The proportions of the populations of children and young people detained varied by jurisdiction as did their distribution across variations of secure settings. Not all jurisdictions had all three kinds of secure settings. Definitions of secure beds varied depending on the use of relational, procedural or physical security. Conclusion: Findings are tentative but suggestion solely considering numerical descriptions of children's detention is misleading; our study highlights ways in which comparative studies may be improved. Within reported jurisdictions, the framework of health, welfare and justice was meaningful but this may not hold true with a wider international application of this method. Open interrogation of this data would be enhanced by the inclusion of children's perspectives.