Within the framework of a national research project ‘Monitoring of the Swiss Local Authorities’ (Schweizer Gemeindemonitoring), the development of Swiss municipalities has been monitored for almost three decades, focusing on performance, reforms, and the political system. To this end, a survey of the Swiss municipal secretaries (Gemeindeschreiber/-innen) and local politicians in the council (executive members) has been conducted periodically at intervals of approximately six years since 1988. These surveys are carried out by the ZHAW in cooperation with the IDHEAP Lausanne (or previous institutions). Since the survey was carried out several times already, both cross-sectional (individual years) and longitudinal analyses (across the various data sets) are possible. Thanks to a high response rate, a comprehensive database on the development of Swiss municipalities has been created which benefits associations involved in local and regional governance, state institutions, the research community, and the public.