The competitiveness of agri-food products depends mostly on their quality. High-quality products meet the consumers requirements and are an attractive export commodity. The purpose of this article is an assessment of changes in quality of selected agri-food products in Poland for several years. Food-producing plants will be also under review. Indicators of changes in the dynamics and structure and functions of trends allow analysis of transformations. The use of these research methods allow to trace the transformations related to the quality of food products in time. The results showed improvement of the quality of meat and milk and the sanitary condition of food-producing establishments.