This study examines the degree of bipolarization of regional per capita income distribution in the European Union between 1977 and 1999. The results obtained reveal a decrease in regional bipolarization in the European context over the study period as a consequence of various factors working in opposite directions. Likewise, the analysis carried out shows that the national component is the main factor explaining regional bipolarization in the European Union, while the geographical location and the productive structure in 1977 seems to have less relevance.