Price differences significantly shape trade and affect consumer behavior. Change in prices of agricultural products imply changes in food prices. Factors shaping the prices of agri-food products can divide into structural factors (for example: area of crops, consumption, import, export) and cyclical factors (for example: extreme weather events, exchange rates). The purpose of this article is to study the influence of supply and demand factors on the purchase prices of selected products on the EU and Polish markets. The main research methods are the econometric causal-effect models. In addition, trend models will allow to determine the direction of development for the prices of analyzed agri-food products. OECD, FAO and EUROSTAT data were used to this study. The results show the relationship between the purchase price of agri-food products and supply and demand factors and allow comparison of these prices in Poland and in the EU. Trend models have helped to set price forecasts for the next two years.