Organic farming has expanded rapidly in Europe during the last decade. In view of the agricultural policy trends, the current socio-political climate and a continuously growing demand for organic products, a further expansion of organic farming seems likely. In view of these prospects, the objective of this study is to provide a quantitative assessment of the impacts of a significant expansion of organic farming in the European Union on agricultural production, markets and the environment. Using and extending the EU-wide agricultural sector model CAPRI, different policy scenarios for a conversion of organic farming to 20 % of the agricultural area in the EU are analysed. The results indicate that such an expansion has a significant effect on several policy-relevant indicators, but this impact is less than often projected on the basis on farm level comparative calculations. This is due to several different intra- and inter-sectoral feedback loops (e.g. market equilibriums, quotas) which can only be captured using a sectoral approach. The model results point to the significant influence the policy instruments, and thus the regional distribution of organic farming and the distribution of converting farm types, have on the extent of potential impacts of a more widespread conversion. This highlights the scope for policy making to pursue policy objectives more efficiently by designing the support programs accordingly.