The decentralisation of policy responsibilities from the national to the local level in the domain of social policies is meant to facilitate a better fit to local conditions, and, consequently, inspire local variation in social policy positions. This article examines two questions: (1) to what extent do Dutch local party branches’ social policy positions deviate from their national mother party and local peer parties and (2) do local conditions explain this deviation? To answer these questions, we developed a dataset including 168 local party manifestos from 27 strategically selected municipalities and 8 national party manifestos. Our analyses show limited deviation in local parties’ positions compared to their national mother party and other local branches of their national mother party. This suggests that the social policies addressed in the party manifestos of local parties seem to reflect a process of institutional isomorphism. Furthermore, the limited deviation that does exist in local parties’ social policy positions is not convincingly larger in municipalities (1) that are smaller, (2) that have higher social benefit dependency, or (3) that have high vote shares for local independent challengers. This is contrary to what can be expected based on the contingency theory.