International cooperation is one of the most important instruments for building a society guided by respect for human dignity and based on the principle of subsidiarity. International cooperation is implemented with the use of various forms and based on different grounds. This article presents one of them – cross-border cooperation, which is carried out between Polish entities and entities in neighbouring countries on the basis of operational programs. The paper presents definitions of international cooperation and cross-border cooperation in order to outline the extent to which operational programs, under which cross-border cooperation is carried out in Poland and within the European Union, will be later presented and compared. These operational programs are closed during the programming period 2014–2020 and are implemented under the European Territorial cooperation, the cross-border cooperation component.