National Statistical Institute of Italy (Istat) realeased recently final results of the last population census, carried out in Italy on 2001. Taking into account the importance of those results for the analysis of the most recent and strutuctural changes on the demographic and socioeconomic situation of the country, it is very opportune to reflect on the quality of these statistical data. This paper takes into consideration this last subject, more precisely one specific population aggregate, that one concerning the foreign resident population, which becomes more and more important, once Italy became an immigration country since the 70’s decade of the past century.

keywords: Population census, foreign population, immigration, data quality evaluation