Much research has been conducted on immigration into Ireland in recent years using data from the Quarterly National Household Survey (QNHS), the official source for labour market data in Ireland. As it is known that the QNHS undercounts immigrants in Ireland, a concern exists over whether the profile of immigrants being provided is accurate. For example, QNHS-based research has shown that immigrants in Ireland are a highly educated group. However, if it is the case that those who are missed by the QNHS are more heavily drawn from among low-skilled immigrants, then the profile being reported and used in other research may be inaccurate. In this paper, we use the Irish Census of 2006 to assess the reliability of the profile of immigrants provided by the QNHS by comparing the characteristics of immigrants in both datasets. In general, we find that the QNHS does indeed provide a reliable picture and that earlier findings on the education levels of immigrants in Ireland hold.