The subject of the thesis is business negotiations in the ASEAN countries. Business negotiation is a mutual process of communication between two or more people with different interests that have mutual agreement or common decision as a goal of this process. International business negotiations are a much more complicated process compared to negotiations in one country because they are affected by various aspects, such as: political and legal pluralism, international economy, foreign governments and birocracy, instability, ideology and culture. Culture, cultural values and understanding cultural values have gained more significant importance. Good knowledge about one's culture has become a main precondition of business success in global market and precondition to doing business in general. Business negotiations' process based on cultural differences is reflected in both verbal and non verbal communucation. This thesis is based on comparative review of cultural differences in international business negotiations in the ASEAN countries, based on communication and cultural differences. General conclusion is that some (small) differences in business negotiations do exist among Indonesia, Malaysia Singapore, Thailand and Vietnam, but also among other countries as well. Business negotiators must be aware of communication and cultural differences in order to avoid interruption of negotiations or potential negative impact on negotiators' reputation or reputation of an organisation.