The accession to the EU and the adopting of the Common Agricultural Policy led to the major changes in the income situation of the Polish agricultural sector. During the membership, the real increase of farmers’ incomes was by over 96% in absolute terms and by over 112% if calculated per 1 worker, in comparison to the situation in the pre-accession period. However, the increase resulted mainly from the growth of subsidies, and to a lesser degree from other factors. The growing influence of subsidies on the income situation of farmers cannot hide the fact that generally the agriculture in Poland, compared to agricultures of the other member states, is characterised by low efficiency. The productive and economic development in the long term can be hardly expected without profound structural changes stimulating the growth of efficiency. Results of both factor analysis and regression analysis clearly indicate the need for such changes. The results show that generally the economic and financial situation of the Polish agricultural sector is determined by its efficiency, whereas the subsidies play a less important role.