For decades, comparative research on the welfare state concentrated on social security systems, neglecting the dimension of social services. The concept of social care was established by feminist analysis as late as the mid 1980s. Subsequently, a growing number of empirical studies on social services for children, the elderly, and handicapped people was published. Theoretical research on the classification of welfare regimes, including social services, concentrated on the range of activities and on the extent of state expenditure for social care. The fact that social care is an important pillar of welfare production at the intersection of state, market, family, and the voluntary sector has been neglected. There are big variations in Western Europe as to how social work has been approached by public policy: we will show that by using the example of religious welfare associations. It is the aim of the Mannheim comparative project to systematically collect data on the qualitative and quantitative dimension of social service provision by the church in Western Europe. In a first part we will explain why in our eyes the study of religious welfare associations is of vital importance for scientific and political reasons. In a second part the design of the research project and the proceedings will be presented. In the last part we summarize the empirical findings.