Our study aims to explore whether simultaneous municipal autonomy and institutional fragmentation foster urban sprawl. We discuss the hypothesis that in such a setting, competition between municipalities to attract development leads to high degrees of urban sprawl. A comparison of the 26 Swiss cantons was carried out using fuzzy-set qualitative comparative analysis combining the aforementioned conditions with other urban sprawl drivers. As a result, four consistent, sufficient combinations of conditions were identified. These combinations show that municipal autonomy and institutional fragmentation are indeed linked to high degrees of urban sprawl. This is especially true when municipal autonomy and institutional fragmentation are combined with the economic triggers of competition between municipalities and oversized designated building zones. These results draw attention to the necessity of stronger supra-municipal coordination within the framework of Swiss land use planning policy.