The aim of the study was to assess the productivity of the Polish agricultural sector compared to other EU countries in the long-term, encompassing the years 2004-2017. The time range of analyzes covered the years 2004-2017, spatial range of analyzes concerned individual EU countries, and the subjective scope of research included representative farms from these countries. Data was from EUFADN. Therefore, a comparative analysis of synthetic indicators of agricultural productivity in 2004- 2006, 2007-2010, 2011-2014 and 2015-2017 was performed. It has been proven that agriculture in Poland, compared to other EU countries, was characterized in the years 2004-2017, almost by the lowest level of resource productivity. The sources of competitiveness of agriculture in Poland in relation to other EU countries result from price differences and not from differences in the productivity of land, capital and labor. The Polish agricultural sector, in the last decade, showed almost the lowest productivity of resources in relation to other EU countries. This was proven by excluding the impact of prices on the differences in resource productivity between EU countries. The increase in the productivity of Polish agriculture is therefore a necessary condition to prevent a progressive decrease in the competitiveness of this sector.