Accession of Poland to the European Single Market generated trade creation and diversion effects, which in turn resulted in a high degree of concentration of the Polish foreign trade in agri-food products with other EU countries. On the one hand, a high share of export to the markets of countries with a stable market economy is a confirmation of the Polish agri-food sector's capacity to compete on the foreign markets. On the other hand, when considering limited capability to increase food demand in the EU it provides grounds for the assumption that further export expansion to a considerable extent will depend on the potential expansion of sale to non-EU markets. In this context significant issues include diversification of target markets and search for prospective markets outside the EU, while they also determine directions of an advantageous export specialization. In the period up to 2021 the USA was the fourth non-EU export partner of Poland in the agri-food sector after the United Kingdom, Ukraine and Russia. The aim of this paper is to evaluate the level of comparative advantages of the Polish agri-food sector on the EU and US markets in 2004-2021 using Widodo's products mapping technique. The study used statistical data from the ComExt database of the European Statistical Office (Eurostat). The conducted studies showed Polish export specializations in the transatlantic trade, as confirmed by high comparative advantages, as well as a positive and steadily improving trade balances for food preparations, including meat, cereal, fruit and vegetable, as well as confectionery preparations, and less processed animal origin products (meat and offal as well as dairy produce). Poland had a disadvantageous competitive position in trade of products complementary in relation to domestic production, which import was necessary. In view of the comparative cost theory the directions of the realized export specialization were rational and should be maintained. While in trade with the other EU countries the competitive position of the Polish agri-food sector was weakened, it was strengthened on the US market. In view of the considerable EU market saturation the improved competitive capacity in the non-EU markets is a positive development, which is a promising finding particularly in the long-term perspective.