The purpose of this review of homeless statistics in Europe is to examine the definitions of homelessness in relation to the categories of the ETHOS typology developed in the previous edition of this review (Edgar et al, 2004). This is the main focus of the report in relation to the evolution of the ETHOS typology. The report also presents the latest available data in relation to this definition but this was not the primary focus of the brief to the correspondents of the Observatory. The issues of measurement and data collection will form the focus of the next review of European statistics on homelessness.