This article presents the analysis of household structures of the foreign population in Spain based on the 2001 Spanish Census. Due to this analysis we are able to explore structures directly related to the acceleration of the migratory flows initiated at the end of the last century, with more complex household structures among foreigners than Spaniards. Results show that the recent increase of migratory flows has modified household structures of the foreign population, which constitutes a good indicator for the status of the migration process as well as for the strategy of each of the national groups.