CONTEXT Life Cycle Assessment (LCA) remains a method of choice for assessing the environmental performance of agricultural systems. However, it is rarely applied to multifunctional extensive production systems, in which livestock use, apart from animal production, maintains a continuous disturbance that sustains the diversity of habitats and species. OBJECTIVE This study aims to assess the environmental impact and biodiversity of extensive ruminant production on semi-natural grasslands (SNG), that is, High Nature Value (HNV) farming across Europe. We collected data from a total of 41 HNV farms in five countries (Finland, Estonia, Spain, Greece, and France) that produce beef, sheep, and goats, and that incorporate (to a varied degree) semi-natural and permanent pastures into production. METHODS We used LCA to assess the potential environmental impact of HNV farms according to global warming potential (GWP100), fossil resource scarcity (FRS), water scarcity (WS) and land use (LU), by using the Solagro Carbon Calculator and OpenLCA software. We assessed biodiversity based on the expert scoring system of SALCA-BD. We compared impacts on per area and per product basis across the farms, and related them to the productivity. RESULTS AND CONCLUSIONS Results revealed a considerable variation in all environmental impacts among HNV farms, explained mostly by the type of ruminants, main product (meat or milk) and the production level. GWP100 per unit in beef product in France was almost twice as high as that in boreal and 3 times more than in Spain, while sheep systems in Greece varied 7-fold for meat. Sheep systems consistently had the highest GWP100, while goat systems used the most land, fossil fuel and water. Small ruminant production in Spain had both the highest land occupation and biodiversity values. Biodiversity was at its highest on farms utilising only SNG for production, which, however, related negatively to the farms' production output. Enteric fermentation accounted for 32% of overall emissions. SIGNIFICANCE This study makes a novel contribution towards a better understanding of the environmental performance and production capacity of HNV farming systems that are often used as examples of multifunctional and sustainable ruminant-based production.