Constitutionalization of family law, as one of the manifestations of the expansion of the influence of fundamental rights in the sphere of private law, is an attempt to reinterpret traditional family rules in light of principles such as human dignity, equality, and freedom. While this process can provide a basis for more effective protection of the rights of family members, it faces challenges arising from the institutional, relational, and self-regulating nature of the family, as well as the limited transformative capacity of judicial interpretation. Employing a descriptive-analytical method and a case study of Judgment No. 9909 dated 18/09/1399 issued by Branch 13 of the Mazandaran Provincial Court of Appeal, this article examines the possibilities and challenges of constitutionalizing family law within the Iranian legal system. The research findings indicate that the said ruling, by interpreting Article 1117 of the Civil Code in light of Articles 20, 22, and 28 of the Constitution and recognizing the role of fundamental rights in determining the limits of the husband’s authority, constitutes a noteworthy example of the judicial constitutionalization of family law. Nevertheless, a critical analysis of the judgment shows that the constitutionalization of family law requires a minimal and protective model that, while preventing undue restrictions on individuals’ fundamental rights, also takes into account the institutional and relational characteristics of the family. Moreover, although judicial constitutionalization can play a corrective role by creating new interpretive patterns and reducing case-by-case injustices, it alone cannot substitute for legislative reforms and structural revision of family laws. Accordingly, the article concludes that the constitutionalization of family law in Iran should be regarded not as an alternative to just lawmaking, but rather as a gradual, intra-systemic strategy for approximating existing law to fundamental values and paving the way for legal reforms.

Keywords: Constitutionalization of law, family law, horizontal effect of constitutional rights, judicial interpretation, wife’s right to employment, Article 1117 of the Civil Code.