In Europe agricultural areas are of great importance to biodiversity conservation. One of the aims of the Common Agricultural Policy (CAP) after 2013 is to avoid additional loss of agriculture-related biodiversity. Farmland biodiversity is a public good that provides ecosystem services necessary for the sustainability of agriculture itself as well as for a sustainable environment as a whole. To evaluate policies such as the CAP and to monitor the development of biodiversity in agricultural areas, specifically designed indicators are needed. Current EU-level indicators of agricultural biodiversity are often limited to a specific species group, for example the group of farmland birds, and are not designed for evaluation of future policies. This study presents a methodology for a new indicator that is targeted specifically at biodiversity in agricultural areas, considering a large variety of species and focussing on policy. The methodology combines maps of the potential occurrence of 132 relevant species (plants and vertebrates) on a 50 km grid, with detailed information (1 km grid) on the influence of environmental pressures on these species. A first indicator map on a 1 km grid for the EU is provided, based on available data. This map shows great variety in the state of the biodiversity of agricultural areas in the EU. Generally speaking, biodiversity in agricultural areas in the south and east of the EU is in a better state than in the west and north. However, spatial variability is high between and even within regions. The presented indicator may be used to explore the dynamics of biodiversity following policy interventions, using the biodiversity map or by modelling the effect of policies on the environmental pressures that form the basis of the indicator. © 2012 Elsevier Ltd.