The determinants and consequences of the naturalization of immigrants is a hot topic in the political debate in Europe. This article compares the effect of naturalization on the income attainment of immigrants in two Scandinavian countries, Denmark and Sweden, using longitudinal register data from 1986 and onward. Sweden is characterized by low obstacles to naturalization, and existing studies provide inconclusive evidence regarding the impact of naturalization on labor market outcomes. Denmark is instead characterized by higher barriers to naturalization, as well as a virtual inexistence of previous studies on the topic. Results, obtained through individual fixed-effect regression analysis, suggest similar effects in both countries. A consistent naturalization premium is detected for immigrants of Asian and African descent, but not for any other immigrant group. The similarity across contexts arguably questions the use of more stringent naturalization laws to promote the economic integration of immigrants.