This article aims to treat the concept of the parliamentary diplomacy. The researchers of international law have argued that international diplomacy has helped to form current the international law. The inter-parliamentary can be defined as a modern phenomenon very different from the traditional parliamentary system. This change is connected to the problems posed in inter-parliamentary, who have no political or geographical boundaries. The inter-parliamentary has its origins in the nineteenth century, with the formation of the InterParliamentary Union to 1889. Today, the concept of inter-parliamentary has taken new dimensions. The success of parliamentary diplomacy is determined by parliamentary delegations composed of leading figures who act with responsibility and patriotism together with diplomats, to solve the problems of their nations. In comparison to national diplomacy, parliamentary diplomacy has flexibility and an opportunity to address important issues of international relations. The parliamentary diplomacy can be studied also in the context of 'inter-union as well as in the context of international organizations. It counts with elements such as to allow a diplomatic process democratic, giving a significant value to international conflicts resolved.