This paper analyses the relationship between production and purchase of milk. At the same time we analyse the purchase and sale of milk at the domestic as well as at the foreign markets using the time series statistical data. We present production of milk, dairy industry, and marketing of milk and dairy products. They are mutually dependent and interactive. The dairy processing industry is one of the three largest sectors in the Slovenian food processing industry. We the entry of Slovenia into the European Union and by the introduction of the Euro, we register substantial changes in the Slovenian dairy industry. These are increasing competitive pressure at the common market and pressures on the farm gate milk prices.