High income inequality accompanied by substantial regional differentiation is still a great challenge for social policy makers in many European countries. One of the important elements of this phenomena is inequality between income distributions of men and women. Gender can affect people’s working lives in different ways. Even if it is illegal for employers in our countries to pay men and women different amounts for doing the same job, there are many other reasons why, on average, we can still observe substantial income differences between men and women. Using data from the European Union Statistics on Income and Living Condition (EU-SILC) 2015, we compared the distribution of income for Italy and Poland, and analyzed the gender gap. No single metric will capture the full range of experiences, so we opted for adopting a set of selected tools. We estimated a Dagum model for each distribution, evaluated summary measures like the Gini and Zenga inequality indices, including Zenga “point” inequality measures dedicated to detecting changes at each income quantile, and compared empirical distributions through a relative approach, providing an analytic picture of the gender gap for both countries. Further, we repeated the analysis in the different macroregions of the two countries and compared results. The study revealed that income inequality in both compared countries varies across gender and regions. In Italy the highest inequality was observed in the poorest region, that is the islands. On the contrary, in Poland the highest inequality was observed in the richest region, the central one. The relative distribution method turned out to be a powerful tool for studying the gender gap.