Across Europe grandparents play very different roles. This paper studies to what extent grandparents' role as providers of child care relates to the country policy context, focusing on public child-care services and parental leave regulation, and to the availability of part-time jobs for women. We also explore whether mothers' needs to combine family and work differently influence the frequency of grandparental child care across countries. The analysis combines micro-data from the Survey of Health, Ageing and Retirement in Europe and macro-indicators from the Multilinks database and Eurostat. We find a clear association between policy context and frequency of grandparental child care. Three models emerge. In countries close to the familialism by default model (i.e. characterised by scarce public child-care services and parental leave), when grandparents provide child care they often do it daily. In countries characterised by defamilialisation and supported familialism policies (with generous public services and parental leave) grandparents take on a marginal role. An intermediate model emerges in countries characterised by a limited offer of child care or parental leave, where grandparental child care complements state support and tends to be offered on a weekly basis. Our analysis corroborates the idea that the highly intensive involvement of grandparents in countries with low availability of part-time jobs for women is influenced by the need (unmet by the welfare) of mothers to combine work and family.