The aim of the article was to determine how court decisions concerning the change of purpose of agricultural land affected the Polish spatial planning system in the years 2014–2023. In order to achieve this aim, the database of decisions issued by the Supreme Administrative Court (NSA) was analysed. It is a collection of all published decisions of the SAC and provincial administrative courts. The database contained decisions issued in the years 2014–2023 in which (taking into account both the operative part of the decision and the justification) the expression “change of purpose of agricultural land” (with declension of the words) appeared. 5324 decisions were identified, from which, after a comprehensive analysis, 142 decisions were distinguished that directly concerned spatial conflicts related to the change of purpose of agricultural land. The research conducted by the authors shows that most decisions confirm the impossibility of changing the purpose of agricultural land. The majority of the complainants are private entities, but there is a significant group of complainants from public entities. A significant part of the complaints concerns local plans and decisions on development conditions.