This study investigates the housing characteristics and the determinants of housing production of the informal housing sector in Alexandria, Egypt. It also examines the impact of land policies on the development of the informal housing sector. Informal housing, by definition, is constructed and acquired outside the legal procedure of land and building registration and without the necessary permissions and approvals. Therefore, there is a little knowledge about it, and its role in the housing market could be underestimated. The aim of this research is to enhance the factual knowledge about informal housing as a basis for future policy development. The findings of this research, based on data collected from a field study conducted in four informal settlements in Alexandria in 1991, include the following: 1. Macro-economic, political, and social structures accelerated the emergence and the development of informal housing settlements, which occurred rapidly during and after times of economic and political crises. 2. Informal settlements are heterogeneous and it is not evident that informal housing is synonymous with marginal housing for poor people. 3. Informal settlements have low levels of public utilities and infrastructure. 4. Income, household size, age of household head, and tenure status of the household are the major variables that explain different patterns of housing consumption and expenditure among informal households. 5. Inhabitants of informal settlements have moved from other areas of the city rather than origins outside Alexandria. Owners are more satisfied with both the units and the neighborhoods than renters are. 6. The determinants of informal housing production are in a dynamic process of change and are self-organized. The general conditions of the overall housing market influence informal housing in similar ways. Informal housing finance depends upon small scale and incremental methods of savings. 7. Implementation of different land policies results in augmenting provision of illegal land subdivisions, increasing land prices and expanding informal land market operation. From the analysis undertaken in this research and previous findings, some policy implications for future planning for informal development become evident.