This article presents the results of a study devoted to the measurement of the income polarization in Romania. In the first part the key methodological issues of measuring polarization are addressed, with emphasis on the polarization indices. To measure the polarization of the household incomes in Romania, which is the subject of the second part of the study, several indices of bipolarization (Foster-Wolfson, Wang-Tsui, Milanoviþ, Esteban-Ray and Esteban-Gradin-Ray indices) and group polarization (Esteban-Ray and Gradin indices) have been used. All indicators show a higher degree of polarization in 2008 as compared with 1995 and 2000.