Cropland, that is land used for the cultivation of crops, is a fundamental resource for feeding the Earth’s population. The loss of the most fertile land owing to urban expansion, infrastructure development and other drivers, has become a prime issue for land systems science and spatial planning. Spatial planning, being about building frameworks to guide the location of development and infrastructures, is a major driving factor for many land-use change processes. However, research on the possible roles of spatial planning in halting the increasing conversion of cropland into urbanised areas is scarce. In this paper, planning instruments for cropland protection currently in force in eleven Western European countries are identified, and discussed according to a framework centred on the different factors and prerequisites promoting the successful implementation of such instruments. Our findings show that the countries investigated have developed a variety of instruments for cropland protection, which can be grouped into two rough categories: (i) prime planning instruments, that is priority areas for agricultural land-use; and (ii) complementary planning instruments, which are national targets to limit land-take and soil function assessment frameworks. Advisory expert panels and pre-emption rights for farmers and farming organisations are also applied complementarily. Our findings indicate that these instruments might be more effective, if they were legally binding all administrative levels and practically applied in multilevel governance arrangements. In addition, we conclude that effective cropland protection requires that planning authorities compensate for the loss of the most fertile land.