By exploiting the potential of social media, disinformation has become an important element of warfare. The region of Central and Eastern Europe (CEE) is particularly vulnerable to disinformation, primarily from Russia. One of the reasons for Russia’s activities in this region’s infosphere is that most CEE countries are members of the European Union and the North Atlantic Treaty Organization (NATO). In this context, Russian disinformation activities aimed at the Three Seas Initiative (3SI) are particularly interesting. The image of the 3SI created in the media is crucial, for it translates into how the public understands, perceives and recalls this format of cooperation. The article aims to reconstruct the image of the 3SI in cases of Russian disinformation identified by the European External Action Service within the EUvsDisinfo project. The article’s methodology is based on a qualitative content analysis of disinformation cases identified by EUvsDisinfo. The article identifies four main frames of disinformation targeting the 3SI, showing that Russian disinformation is focused on undermining the credibility and integrity of this cooperation, both among Initiative countries and between them and their international partners.