Accession to the European Union is expected to intensify the competitive pressure and substantially alter the political - economic condition in Bulgaria. This contribution provides a quantitative assessment of the impact of implementation of the Common Agricultural Policy (CAP). It is based on results which are calculated using EISM (European Simulation Model). The model covers the supply of eighth primary agricultural commodities (wheat, maize, barley, sunflower seed, beef, pork and poultry meat, milk) and demand for food products from Bulgaria. The paper consists of short description of the modeling approach then the assumptions which have been made regarding the preliminary negotiations for accession are explained. Subsequently the evaluation of the impacts of accession focused on change in producer prices, production and incomes from farming.