Men and women wage differences is a widely discuss topic in the literature. Some authors point the fact that size of gender wage gap (GPG) is not the same across wage distribution. GPG ratio is accelerating at the top of it. Thus, the main goal of presented study is to analyse impact of outliers (top earners) on the values of GPG ratio and results of its decomposition. In addition we compare outcomes obtained for Spain and Poland. Elimination outliers from the sample will reduce values of men and women wage gap ratios not only in unadjusted form but in adjusted form as well. Study is based upon the Eurostat’s Structure of Earnings Survey (SES) individual data in respect of 2014. In the paper we discuss results of Oaxaca-Blinder decomposition (in extension proposed by Oaxaca and Ransom) obtained for Spain and Poland. Obtained results indicated two points above all. Firstly, although unadjusted GPG ratios for Spain and Poland differ significantly, the adjusted GPG ratios are at the same level (about 15%). Such situation shows the real men and women wage differences are at the same level in both countries. This is an additional indication that women situation on Polish labour market in similar to the Spanish one. Secondly, after elimination of outliers the values of GPG measures (in adjusted and unadjusted form) decreased, as was expected. These falls came to approximately 3 p.p. It can be considered as significant change.