The notion of institutional completeness developed by French Canadian sociologist Raymond Breton is a conceptual tool devised to assess the institutional dimensions of the social integration of individuals belonging to minority ethno-linguistic groups. On the basis of this notion, this article proposes a neo-institutional analysis of the Sorbs of Lusatia. It takes a closer look at Sorbian community-based institutions and organizations as well as formal and informal institutional constraints faced by this small Slavic people since the German unification of 1871.