This study investigates juristic Shi’i guidelines as well as philosophical and legal perspectives on marriage in the Iranian contemporary context where specific interpretations of Twelver Shi’a are encoded in civil law. The study discusses three important factors that contribute to the legal and juristic complexity of Shi’i marriage: (i) length of marriage, including discussions on permanent and temporary marriage; (ii) registration of marriage and the problem of unregistered marriages; and (iii) age of marriage and the issue of child marriage. All three factors have been significantly present in the social, public and political debates on marriage and reproduction as well as in women’s and children’s rights movements in Iran. I outline some of the potential social implications and harmful effects of the existing problematic discourses of temporary, child and unregistered marriages. After discussing the three factors and the diversity of marriage practices, the study contextualizes the existing diversities within the broader Shi’i political and religious discourses.