The objective of this article is to analyse the role played by the different components of human capital in the wage determination of immigrants in the Spanish labour market. Using microdata from the Encuesta Nacional de Inmigrantes, we find that human capital of immigrants acquired in Spain presents higher returns than human capital obtained in home countries, reflecting the limited international transferability of the latter. This result is reinforced by the strong heterogeneity observed in wage returns to different kinds of human capital across immigrants from different origins and, in particular, by the fact that immigrants with the higher returns to human capital acquired in their home countries are those coming from other developed countries and Latin America, the two regions more similar to Spain in terms of development and/or culture.