This trans-cultural comparison was undertaken to describe the the needs of homeless people for mental health services in London and New York and the way services are meeting these needs in the two cities. An individual needs assessment procedure was undertaken on a random sample of individuals from a New York shelter for men to assess their needs for psychiatric services. These needs were compared with the needs of a sample of homeless men from hostels of an Inner London health District. The residents of the New York shelter were younger and many of them were in full-time employment. They had fewer physical and psychiatric problems compared with the London sample but much more substance abuse and in particular drug problems. Despite the similarity of the disablement of the two samples and in spite of the higher levels of service provision in New York, the unmet needs of homeless people were significantly higher in the New York sample. The explanation of this puzzling finding may lie in the institutional n...