This article attempts to engage with developing critical realist perspectives in housing and urban policy to propose a more rigorous framework for analysing the causes of homelessness. The article is framed mainly in the context of the extensive UK literature on this topic, but the theoretical arguments it pursues are intended to have wider applicability. It contends that the prevailing “new orthodoxy” in explanations of homelessness, which attempts to integrate both “structural” and “individual” causes, is useful at a descriptive level, but is unsatisfactory at a more profound conceptual level. Previous attempts to provide more theoretically informed accounts of homelessness - including positivist, social constructionist, feminist and postmodernist/poststructuralist - are also critiqued from a critical realist standpoint. The complex, emergent and non-linear explanatory framework employed by realists is argued to enable a coherent causal analysis to be maintained in the face of the diverse circumstances associated with homelessness. Poverty, spatial concentrations of disadvantage and domestic violence are used as illustrative examples of potential inter-related causes of homelessness to sketch out a preliminary realist account of this persistent social problem.