One of the theoretical principles of taxation is that a tax should impose an equal burden on taxpayers. The objective of this work is to investigate empirically, whether this principle is followed by the personal income tax in Brazil. Our results indicate that the personal income tax in Brazil closely approximates an equal sacrifice tax.Este trabalho visa verificar a hipótese de que o Imposto de Renda Pessoa Física (IRPF) impõe um sacrifício equitativo sobre os contribuintes. Usando a metodologia desenvolvida por Young (1990), resultados empíricos ex-post confirmam tal hipótese para o IRPF durante a década de 1980.