Two main arguments are presented in this article. First, when alternatives for the future design of local government are debated, a government needs to address two basic issues simultaneously: (a) how big (and hence how many) municipalities ought the political system have?, and (b) how strong and well secured ought the principle of local self-government be in the constitution? Second, by using these two questions as guides for our analysis, we argue that there are instrumental as well as substantial reasons to guarantee a strong local self-government in the constitution. However, such a reform needs to be complemented by a politically neutral body of regulations that, under given conditions, secures geographically concentrated minorities a right to secede. Although we use the Swedish case as the empirical base for the discussion, our analysis has a bearing on recent developments in, for example, the other Nordic countries and England, where amalgamations at the local level have been on the agenda throughout the past decade.