In 1992, with the adoption of the Maastricht Treaty, a new institution, namely EU citizenship, was created. The treaty introduced a qualitative change in the sphere of political and legal position of citizens of the Member States, who gained in these spheres a number of new powers. One of them is the right to diplomatic and consular protection. The analysis of these two rights leads to a conclusion about the great discrepancy that exists between treaty guarantees and the effective exercise of this right. The Member States did not agree with third countries on this subject, which is a requirement of international law. Secondary law also allows only a partial exercise of the treaty’s right to care in the territory of third countries. It has been reduced only to consular assistance and is still narrowly understood. The treaty law of EU citizens remains therefore at a very early stage of development.