Agriculture is one of the primary drivers of biodiversity loss. One agricultural policy instrument in this context is the spatial coordination of conservation efforts by farmers through ecological network projects, which provide spatially connected conservation areas, such as areas under agri-environmental schemes. However, the success factors for establishing ecological network projects, as well as their effects on various economic and ecological outcomes are still poorly understood. To obtain a deeper understanding of these important questions, we assembled a novel and comprehensive geospatial dataset of network project perimeters at the municipality level in Switzerland. Within these network project perimeters, farmers are eligible to enroll their agricultural plots that need to be managed according to the regulations of agri-environmental schemes. The dataset covers 98% of Switzerland’s total land surface, including areas with and without ecological network projects. The dataset enables linkage with other data sources for future analyses, such as estimating the effect of network projects on e.g. the take-up of other agri-environmental schemes, farm income and biodiversity. To improve these future analyses, the dataset contains additional information such as the area and start year of an ecological network project, as well as the geographical share of ecological network projects in a municipality.