Abstract A major shortcoming in the existing literature on welfare state legitimacy is that it cannot explain when social policy designs follow public preferences and when public opinion follows existing policy designs and why. Scholars examining the influence of public opinion on welfare policies as well as scholars investigating institutional influences on individual welfare attitudes find empirical evidence to support both relationships. While a relationship in both directions is plausible, scholars have yet to thoroughly investigate the mutual relationship between these two. Consequently, we still do not know under which circumstances welfare institutions invoke public approval of welfare policies and under which circumstances public opinion drives welfare policy. Taking a quantitative approach to public opinion and welfare state policies in the Netherlands, this paper addresses this issue in an attempt to increase our understanding of welfare state legitimacy. The results show that individual opinions influence relatively new policies, policies which are not yet fully established and where policy designs are still evolving and developing. Social policy, on the other hand, is found to influence individual opinions on established and highly institutionalised policies, but does not influence individual opinions in relatively new areas of social policy.