The special feature of temporary agency work is that the employee does not work for the agency which concludes the employment contract with them, but for a third party, the user company, with which the agency enters into a civil law contract for the remunerated transfer of workforce. The article summarises how an international element can appear in this tripartite employment relationship. It covers the rules under which an agency may conclude an employment contract with a foreign employee and also the cases where the agency and the user company are established in different states. Although Hungarian law generally prohibits third-country nationals to work in Hungary as agency workers, this is made possible by an expanding range of exceptions. The article explores the labour law and social security law situation of third-country agency workers in Hungary.