The paper deals with the earthquakes that took place in the Kaliningrad region (Russia) on 21 September 2004 and were felt in the territories of Poland, Lithuania, Latvia, Estonia, Belarus and Finland. Data on space and time co-ordinates and dynamic parameters of these earthquake foci available from international centers and various seismological groups are analyzed. A degree of reliability of the results obtained is discussed. The epicentral zone of the Kaliningrad earthquakes is found within the western part of the old East European Platform (EEP). The seismotectonic map presenting the territories of Belarus and the Baltic States was considered, and the Kaliningrad-Lithuanian potential seismogenic area was analyzed. Methods used to outline possible earthquake zones when seismic zoning of the Belarusian-Baltic region was carried out were verified in practice and, actually, made possible a long-term forecast of earthquake origination in Kaliningrad.