Cilj rada je proučiti oporezivanje dohotka u Belgiji, Estoniji, Njemačkoj, Slovačkoj i Hrvatskoj i donijeti zaključke o progresivnosti u oporezivanju dohotka. Nakon proučavanja pravila poreznih sustava i izrade modela za promatrane zemlje, izračunat je porezni teret i napravljena njegova dekompozicija za različite tipove obitelji i različite razine dohotka. Doneseni su sljedeći zaključci: Oporezivanje dohotka je progresivno u svim promatranim zemljama, osim Njemačke gdje oporezivanje nije progresivno za neke razine dohotka zbog regresivnog djelovanja doprinosa. Najveći porezni teret za dohodak samca, za gotovo sve razine dohotka, je u Belgiji. Pri razini prosječnih dohodaka, najmanji porezni teret za dohodak samca je u Hrvatskoj, a slijede Estonija, Slovačka i Njemačka. No, pri razini dohotka od 250% prosječnog, najmanji porezni teret je u Estoniji, a slijede Slovačka i Njemačka i Hrvatska te, s najvećim teretom, Belgija. Najveći porezni teret za dohodak obitelji s dvoje djece u kojoj samo jedan od supružnika zarađuje je u Belgiji. Na razini prosječnog dohotka Hrvatska ima najmanji porezni teret, a slijede Slovačka, Estonija i Njemačka. No, pri razini dohotka od 250% prosječne plaće, Njemačka ima najmanji porezni teret. Slijede je redom Estonija, Slovačka i Hrvatska. Oporezivanje prosječnih plaća drugih zemalja po pravilima hrvatskog poreznog sustava ukazuje da je porezni klin na dohodak samca manji u Hrvatskoj u usporedbi sa svim drugim državama, osim Njemačke. Porezni klin na dohodak obitelji s dvoje djece u kojoj samo jedan od supružnika zarađuje je manji u Hrvatskoj samo u usporedbi s Estonijom i Slovačkom. The purpose of this study is to do the research on taxation of wages in Belgium, Estonia, Germany, Slovak Republic and Croatia and to draw conclusions concerning the progressivity in taxation of wages. Firstly, the rules of tax system are studied and models for each country constructed. Using those models, tax burden is calculated and its decomposition made for different types of families and different levels of income. The following conclusions are drawn: Taxation of wages is progressive in every country, except Germany, where the regressive effect of social security contributions makes the system nonprogressive for some levels of income. The highest tax burden on single person’s income, for almost all levels of income, is found in Belgium. At the average level of income, the lowest tax burden on single person’s income is in Croatia, followed by Estonia, Slovak Republic and Germany. However, if the income is 250% of the average, the lowest tax burden is in Estonia, followed by Slovak Republic, Germany, Croatia and, with the highest tax burden, Belgium. The highest tax burden on income of family with two dependent children, and in which only one spouse earns income, is in Belgium. At the average level of income, the lowest tax burden is in Croatia, followed by Slovak Republic, Estonia and Germany. However, if the income is 250% of the average, the lowest tax burden is in Germany, followed by Estonia, Slovak Republic and Croatia. Taxation of average income of other countries using the rules of Croatian tax system shows that tax burden on income of a single person is lower in Croatia when compared with all the other countries, except Germany. Tax burden on income of a family with two dependent children, in which only one spouse earns income, is lower in Croatia only when compared to Estonia and Slovak Republic.