Very little work has examined the question of household structure in the Arab region, despite the fact that there has been speculation that changes in household patterns have been occurring in recent years due to modernization, urbanization and changing marriage patterns. Using a number of primary data sources, including household surveys from Lebanon, Yemen, Syria, and Egypt, as well as analysis by historians that uses archival sources, this paper compares household structure patterns across time and space, to answer the question—how have household patterns changed and do observed changes provide insights into the impact norms and/or structural factors have and will play in shaping household patterns? The data suggest that while often perceived as being the dominant household structure, extended family households are not the norm in the Arab world, nor have they necessarily predominated since the 1800s. In addition, patterns vary considerably across communities, with extended family households occurring more frequently in Syria and Yemen. Some trends that provide insight into the future, as well as being suggestive of possible changes in norms, include: the rising age of marriage; the increasing likelihood that women in particular will never marry; and the increasing ease, despite high levels of youth unemployment, for young people, including young women, to set up their own households. These trends also raise numerous questions about how much changes that are occurring are a function of individual choice or are shaped by cultural or economic pressures. Patterns currently being observed also provide insights into changes that are likely to occur in the future, since current trends suggest that future household patterns may be quite different in the coming years, and that youth, and in particular young women, may be in the process of gaining more autonomy in a number of countrie