For a few years now, the responses of sub-state actors to immigration in multi-level states has been a productive research area. Several case studies, a few (edited) books and comparative studies describe patterns of policy and party positions’ divergence and convergence across regions, and draw tentative conclusions on how to interpret these patterns. This chapter proposes a meta-analysis of this nascent research field. It evaluates the used typologies to describe the variant sub-state actors’ responses as well as the explanatory variables for regional convergence and divergence in the distinct fields of immigration policies and integration policies. There is a specific focus on sub-state nationalism and its relation to immigration.