The paper looks at personal income tax (PIT) in Poland from the perspective of its progressiveness, redistribution effect and influence on prosperity. Household budget surveys carried out by the Central Statistical Office (GUS) in 2003-2005 are the main source of data. The statistical and econometric analysis included in the paper takes into account some basic measures of tax progression. The author also uses a decomposition approach to determine PIT’s effect on the average tax rate in the country. The empirical study conducted by Aksman shows that even though Poland’s PIT is progressive, its overall redistribution effect is not very strong; in the analyzed period it reduced household income inequalities by only 5.22% on average. This is mainly due to a low effective tax rate, Aksman says. What’s more, PIT leads to a decline in prosperity measured with the Sen index; in the analyzed period of time prosperity declined by 11.23% annually on average. With PIT, “poverty aversion” is stronger than “inequality aversion,” the author says, which means that the loss of prosperity resulting from the fall in average income is greater than the increase of prosperity resulting from reduced income disparities.