Consanguineous marriage has been a preferred marriage pattern in Iran. Studies have considered consanguineous marriage as a traditional pattern of marriage which is more prevalent among people with traditional characteristics and family background. Using data from the "2001 Household Socio-Economic Characteristics Survey", this paper examines the level, trend as well as social, cultural and demographic correlates of consanguineous marriage in Iran. The results indicate that despite the fact that Iran has been affected by modernization, urbanization and industrialization forces during the last decades, the level of consanguineous marriage has been relatively stable and constant during this period. The findings also confirm the higher incidence of consanguineous marriage among people with traditional characteristics and show distinct levels and patterns of consanguineous marriage among different ethnic groups. Comprehensive studies using qualitative methods are needed to deepen our understanding on the social, cultural and economic aspects of consanguinity in Iran.