The development of multinational corporations, throughout the history, has depended on the development of the world economy, increase of globalisation, technology and informatisation. Today, they are the carriers of the world economy and use their dominant position to seize the best opportunities offered in the market. The fact that the world has become a global village helps them significantly, in addition to the outstanding interconnection that has made everything possible to reach. With the arrival of a multinational corporation to a domestic market, competition increases and a domestic country is encouraged to develop in business and social terms. Also, new workplaces are opening and unions play an important role because they represent employees in negotiations considering their rights. The aspect of unions' work refers to the defence of employees' rights and their representation in front of the employers. Their role has been changing throughout the history and the scope of their activity and work has been expanding. The primary purpose of this work is to explore the role of the unions, as representatives of employees, in the multinational corporations in Croatia. The questionnaire has been created following this aim, serving as an instrument to collect the data. It was delivered to the representatives of the union commissioners in each multinational corporation, covering the entire Croatian territory. The questionnaire will give an insight into the attitudes and practice that multinational corporations have regarding unions and their role in multinational corporations. This research included 21 participants.