Agricultural production is subject to continuous economic and structural changes. Since the 1990s economic and organizational factors have exerted greater influence on agricultural production than environmental conditions. An important determinant affecting farming production was Poland’s accession to the EU, where agriculture was covered by Common Agricultural Policy. Proportion of plant products does not go directly to the market; it is processed on farms into animal products. At the same time, however, what has been developing for years are unfavorable relations between crop and animal products. The reasons for this state of affairs are complex. One of the ways to improve the results of agricultural production is specialization. This is quite a broad concept, embracing the research issue concerning agricultural production structure and directions of agricultural production, especially regarding commercial production which are defined in literature as directions of agricultural specialization (Kulikowski 2003). The aim of the study is to present changes in the regional specialization of crop and livestock production taking place in Poland in the years 2004‑2019. An attempt was made to answer the question in which agricultural production does a given region specialize and to what extent? The following research hypothesis was adopted: changes in the specialization of agricultural production in the regions are influenced by farmers benefiting from direct payments and other forms of financial aid under the Common Agricultural Policy. For the research on the regional specialization of agricultural production, the location quotient based on the share of crop and livestock commodity production in commodity production was used. The location quotient, apart from providing a static picture of the situation for comparative analyzes, allows for comparisons with regard to the dynamics of the specialization index, and to indicate differences in the dynamics of changes in individual agricultural production specializations. In the investigated period, crop production which is more dependent on climate conditions than animal breeding was much more diversified (changed over time). Western voivodships achieved a high level of specialization in plant production. It resulted from the agrarian structure of these regions, where large farms dominated. The lack of specialization in plant production was typical of the following voivodships: Podlaskie, Warmińsko-mazurskie and Wielkopolskie. With regard to animal production, the situation was different. The share of commercial animal production in the general commercial output was primarily affected by an apparent increase in the share of commercial milk production. This concerned north-eastern voivodships: Podlaskie and Warmińsko-mazurskie, which specialized in beef production as well. Wielkopolskie Voivodship also reached a high level of specialization not only in beef but mainly in pork production.