This article addresses comparative research on what has come to be called, in (British) English, 'child protection' or, rather differently, in Finnish 'lastensuojelu'. In developing a cross-national research project on lastensuojelu/child protection practices in England and Finland, we found it necessary to go back a few steps, to address what might usually be considered as 'background issues'. This article discusses the welfare state traditions in both countries, especially with respect to families and children, in order to contextualise the focus of ongoing qualitative research on micro comparisons. When comparing the mundane practices of child protection and the ways problems and clienthoods are constructed, as in this study, historical, social, cultural and linguistic issues matter. Indeed, very basic concepts such as 'child protection' and 'child protection case' become problematic in the comparison.