This paper introduces a special issue of habitat International on land tenure and property rights. It sets the scene for case studies carried out in countries around the world commissioned by the author as part of a research project updating previous research on innovative approaches to tenure for the urban poor in sixteen countries. The research reviewed changes in the selected tenure systems and place them in a wider context of local land and housing markets. A key feature of the paper is a typological framework which enables policy makers or others to identify the range and distribution of statutory, customary and informal tenure categories in a city, the de facto levels of security provided by each and the various property rights associated with them. The paper demonstrates that tenure systems form a continuum of categories and that policies need to recognise crucial distinctions between these if policy objectives are to be achieved. The role of tenure policy in facilitating or inhibiting security and rights for vulnerable groups, such as tenants and women is discussed and proposals made for implementing a pro-poor tenure policy. The paper concludes by introducing the case study papers.