This overview of research on homelessness in the EU draws largely on the work undertaken by the European Observatory on Homelessness since its formation in 1991, supplemented by secondary literature from other sources. There is considerable evidence on homelessness in Europe but our knowledge remains very uneven with a lack of data and understanding on some aspects of homelessness. More crucially, there is relatively little research in the South and in the Central and East European member states. At EU level, the variations in definition that ETHOS will soon hopefully help address, have hindered the development of a wider perspective and consideration of this social problem at the supra national level. The following summarises the key findings from the overview.