Poland's accession into the EU involved meeting EU standards with respect to milk quality. The collection of the highest quality raw milk became a priority for the Polish dairy plants, because only such raw material can be used in the production of the best quality dairy products that are required by consumers. Therefore, all dairy firms that wanted to be a match for other competitive dairy plants, had to comply with all quality standards considering the following steps: raw milk output, milk collection, milk processing and sales of dairy products. A group of provinces with a big share of extra class milk was separated in the result of dairy plants efforts and their cooperation with dairy farms. The provinces of the Northern and Eastern Poland (Podlaskie and Warminsko-Mazurskie Provinces) belong to this group. The stable improvement of raw milk quality needs compliance with many conditions, for instance: expenditure of time, high costs, expenditure of work etc. The above is confirmed by the example of Dairy Cooperative in Hajnówka. This cooperative achieved a great success in the field of the improvement of raw milk quality. The cooperation between the cooperative and milk producers made it possible. But the main base of this cooperation included specialist advisory service and financial backing aimed at modernization of dairy farms.