The article titled Social Issues in the Transatlantic Trade and Investment Partnership Negotiations discusses selected issues that are subject to bilateral negotiations from the angle of the interests of citizens and consumers in the European Union and the United States. The main emphasis was placed on regulatory differences in the social sphere between the European and American markets, which concern, for instance, security and health protection standards, worker rights, as well as standards for environmental protection and movement of people. Furthermore, the article broadly discusses the problem of the arbitration mechanism between states and investors (ISDS), which gives rise to considerable controversy during the negotiations, especially on the part of the opponents of TTIP. Those opponents believe that this instrument could constitute a threat to the functioning of European rules on social services and health protection because American investors show particular interest in taking advantage of these procedures to protect their interests in these areas. There is concern that including ISDS in TTIP will in fact limit EU’s sovereignty in adopting higher standards of health and environmental protection or worker rights. The last of the issues presented in the text is free movement of natural persons between the EU and the US markets. This problem concerns especially some EU Member States, such as Poland, Bulgaria, Romania, and Cyprus, which remain outside the US Visa Waiver programme. TTIP proposes that the applicable regulations should govern primarily the movement of workers within transnational corporations and liberal professions. As a matter of fact, social issues could decisive for the outcome of the negotiations. The sense of threat and the vision of the lack of protection of social privileges and rights could effectively halt the process of accepting the agreement both in the EU Member States and in the United States.