EU membership status strongly affects the profitability of dairy industry. With the EU accession, the relations between farmers and the dairy industry are changing. In addition to this, the dairy industry itself will be exposed to foreign competition. Depending on the current relations, pace and intensity of this change will depend also on the effects of the EU accession for the dairy industry. However, the Serbian dairy industry will be challenged in the future by the accession to the EU, as is Croatian dairy industry at the moment. This process has been concluded for the Slovenian dairy industry. Dairy industry in Serbia is more profitable than the Slovenian and Croatian dairy industry, despite comparatively worse conditions of the business environment. The profitability of dairy industry in Serbia is a consequence of high prices, lower production costs and lack of EU legislative regarding competition and free market. In all three countries under observation, there is the dominant influence of the leading companies. Consolidated data suggest that market leaders are regional players that greatly exceed national boundaries.